The commercial use of segmentation and predictive modeling

Decision Support Systems 34 (2002) 471 – 481
www.elsevier.com/locate/dsw
The commercial use of segmentation and predictive modeling
techniques for database marketing in the Netherlands
Peter C. Verhoef a,*, Penny N. Spring b, Janny C. Hoekstra b, Peter S.H. Leef lang b
a
Department of Marketing and Organization, School of Economics, Erasmus University Rotterdam, Office H15-17, P.O. Box 1738,
3000 DR Rotterdam, The Netherlands
b
Subdepartment of Marketing and Marketing Research, Department of Economics, University of Groningen, Groningen, The Netherlands
Accepted 28 February 2002
Abstract
Although the application of segmentation and predictive modeling is an important topic in the database marketing (DBM)
literature, no study has yet investigated the extent of adoption of these techniques. We present the results of a Dutch survey
involving 228 database marketing companies. We find that managers tend to rely on intuition and on the long-standing methods
RFM and cross-tabulation. Our results indicate that the application of segmentation and response modeling is positively related
to company and database size, frequency of customer contact, and the use of a direct channel of distribution. The respondents
indicate that future research should focus on models applicable for Internet marketing, long-term effects of direct marketing,
irritation from direct marketing offers, and segmentation and predictive modeling techniques.
D 2002 Elsevier Science B.V. All rights reserved.
Keywords: Database marketing; Modeling; Customer relationship management; Implementation
1. Introduction
Among business practitioners and marketing scientists today, there is an increasing interest in customer relationship management (CRM) [13,14].
Customer databases and the analysis of the data they
contain are essential ingredients of CRM [27]. The
use of statistical techniques for analyzing customer
data, thereby providing information for marketing
decisions, is an important element of database marketing (DBM) and data mining (e.g., Ref. [21]). Theo-
*
Corresponding author. Tel.: +31-10-408-2809; fax: +31-10408-9169.
E-mail address: verhoef@few.eur.nl (P.C. Verhoef).
retical work in the field of DBM has focused on the
development, improvement, and comparison of (new)
statistical techniques (e.g., Ref. [6]). These techniques
are mainly used in segmentation or response modeling. Segmentation in DBM (also called list segmentation) serves to group customers into clusters, which
are internally homogenous and mutually heterogeneous, implying that the members of a segment react to
(direct) marketing actions similarly, but differently
than members of another segment [31,p,3] Predictive
modeling in DBM refers to the prediction of a
response to a mailing or contact, for example, order,
sales volume, and so on [28,p,187]. In the DBM
literature, a number of techniques, such as crosstabulations, CHAID, probit analysis, and neural networks, have been examined that can be used in
0167-9236/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 1 6 7 - 9 2 3 6 ( 0 2 ) 0 0 0 6 9 - 6
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P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
segmentation and/or predictive modeling (e.g., Refs.
[5,6,9,22,23,28,34,35]). Despite the wide availability
of this literature, no study has yet investigated the
extent and nature of the commercial use of segmentation and predictive modeling (techniques). Hence,
given the increasing importance of customer relationship management and DBM, we report on the commercial use of segmentation and predictive modeling
techniques in DBM. Using a survey among companies performing DBM in the Netherlands, we specifically address the following seven outstanding issues:
1.
2.
3.
4.
5.
6.
7.
Which characteristics of customers and prospects
are practitioners saving in databases?
To what extent is segmentation employed and
how do database marketers perform it?
How prevalent is the use of response modeling
for selecting consumers in DBM?
Which techniques do database marketers use for
segmentation and/or predictive modeling?
What is the relation between the use of analytical
segmentation and predictive modeling techniques
for database marketing and firm characteristics?
Does the stated performance of the companies
database analysis activities depend on the employed methods?
Which research issues do practitioners deem most
important for study in the future?
The structure of this paper is as follows. A description of our data collection is given in Section 2.
Subsequently, we present the results of our analysis in
Section 3. We conclude with a summary of our
findings, research limitations and future research
issues in Sections 4 and 5.
2. Data collection
We define the target population for our research as
all companies in business-to-consumer markets that
use DBM techniques with a customer database in the
Netherlands. In the Netherlands, direct mail accounts
for approximately 30% of the advertising expenditures, which indicates the importance of DBM [29]. A
commercial list of a direct marketing (DM) services
provider was used as the basis for our sampling frame.
Self-administered questionnaires were mailed to the
persons responsible for database marketing in 1678
companies in October 1999. A personalized cover
letter explaining the purpose of the study and stressing
the confidentiality of the response was included. The
mailing results in responses from 290 companies,
which is a 17.3% response rate. Sixty-two questionnaires are excluded from the analysis because the
companies are not active in the business-to-consumer
market, do not have a customer database, or did not
fill in the questionnaire correctly. This results in a
final usable sample of 228 companies (13.5%). We
tested for non-response bias by comparing the last 50
respondents with the rest of the sample [1]. As these
tests do not reveal any significant differences, we
conclude that there is no non-response bias.
The survey instrument contains 43 structured,
closed-end questions concerning the company’s (database marketing) activities, the content of their customer and/or prospect database, the use of database
marketing segmentation and selection techniques, and
the respondents’ opinions on important issues for
future research. In order to assure good wording of
the questions, drafts of the questionnaire were tested
with a panel of four marketing academics and seven
DBM practitioners.
The sample can be described as follows. The mostrepresented branch in the responder universe is financial services, which is well known for the application
of DBM [8]. Charities comprise 18.4% of the
responding institutions. A majority of the respondents
holds a marketing function (76.2%). The median
number of employees at the responding companies
is between 50 and 100. The majority of the companies
(81.1%) use direct marketing as a channel of distribution. Most responding companies (71.1%) have
started their DM operations more than 5 years ago.
Hence, we have a relatively experienced responder
group. Direct mail is the most frequently employed
direct marketing medium (95.2%). Telemarketing is
utilized by 64% of our sample, while catalogues are
sent by 27.6%. Relatively few responders (25.4%) use
e-mail as a direct medium. These media are mainly
used to sell products (78.6%), to maintain relationships (62.7%), to provide information (53.6%), and to
attract new customers (40.6%). Sixty-two percent of
the organizations in our sample have a customer
database consisting of more than 50,000 customers.
P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
Table 1
Renting and buying of external data for customers and prospects
(N=228)
Type of information Individual level
Zip level
Customers Prospects Customers Prospects
Name, address
Socio-demographic
Lifestyle
Credit information
Purchase behavior
15.8
20.2
14.5
3.9
5.7
64.0
14.5
23.7
3.1
7.9
N.A.
24.1
21.5
5.3
N.A.
N.A.
34.6
27.2
5.3
N.A.
Based on these figures, we conclude that the sample
consists of companies with sizeable customer databases utilizing all types of DM media and striving for
a number of DM objectives.
3. Results
In this section, we describe our empirical results.
Thereby, we will subsequently deal with all stated
research questions.
3.1. Available customer information
To a great extent, the precision and depth of a
company’s database determines the potential of database analysis to increase profitability [7]. From a
modeling point of view, a lack of customer data can
result in the omission of relevant variables and thus
might lead to incorrect interpretations and poor predictions [15,Chapter 15,and 21]. Companies can collect data themselves or buy or rent data at an
individual or zip code level from external suppliers.
Data at the individual level are naturally more spe-
473
cific. However, individual data are also more expensive and are not always directly available [23].
Organizations should make a trade off between the
cost of renting additional data and performing more
effective modeling [16]. The majority of the companies we studied do not rent or buy external data for
their current customers (Table 1). The most popular
externally supplied information on customers is sociodemographics. For prospects, 64% of the organizations rent lists for the purpose of obtaining names and
addresses. As in the case of prospects, individual level
data are more costly and less available, companies
report a higher incidence of zip level than individual
level purchase or rental.
Table 2 shows that name and address are the most
widely stored characteristics. Furthermore, approximately 60% of the companies keep valuable purchase
history data [24], such as the type of product purchased, the date of the first purchase, and the amount
of following purchases. Data that must be purchased or
gathered by questionnaires, such as socio-demographic data, lifestyle data, satisfaction data, and
purchase data from other companies, have very low
coverage, presumably due to their high cost. The lack
of data on purchase behavior at competitors implies
that companies are not able to calculate customer
share, which is considered to be important in CRM
[20]. The source of the customer and the channel of
purchase, which can be used to evaluate the performance of the utilized channels and media, are stored by
more than half of the respondents [11].
3.2. The use of segmentation
One hundred and sixty respondents (70.1%)
employ segmentation in their database marketing
Table 2
Type of customer characteristics stored in the customer database (N=228)
Characteristic
Percent
Characteristic
Percent
Name, address information
Date of first purchase
Source of customer
Type of product purchased
Amount of first purchase
Number of offers
Date of all previous purchases
Amount of all previous purchases
97.8
73.9
73.0
68.6
61.9
61.5
56.6
56.6
Channel of purchase
Response type
Offer characteristics
Interaction information
Socio-demographic information
Lifestyle data
Satisfaction data
Purchase data (other companies)
50.4
48.7
46.5
42.5
34.5
17.3
12.4
7.5
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P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
activities. Specific questions referring to segmentation
strategy in the questionnaire regard three issues:
The purpose of the segmentation: how are
consumers in different segments treated differently?
The criterion variable: how should consumers in
different segments react differently to the offers
they receive?
The segmentation variables: which customers’
characteristics determine into which segment the
customer will be allocated?
It is remarkable that 90.0% of the companies
employ segmentation for the purpose of target selection (Table 3). Fewer respondents report its use for
varying the treatment or timing of treatment of customers. Almost 27% of all responding companies use
segmentation to build predictive models per segment.
Not unexpectedly, most companies seek segmentation
rules that discriminate groups with differing response
rates. Many companies also classify customers such
that purchase amount is homogenous within a segment. Discriminating profitability is the purpose of
segmentation at only 42.8% of the companies, but
profitability is highly correlated with both response
rate and purchase amount. The discrimination of
levels of creditworthiness interests only few companies as a purpose of segmentation. From a historical
perspective, RFM variables are the most employed
characteristics on which to base segmentation [2].
Respondents value recency as the most discriminating
characteristic for segmentation. Only 32.1% report
segmenting on purchase amount, but 61.6% report
discrimination in purchase amount as a purpose of
segmentation. In line with the availability of customer
characteristics, lifestyle and socio-demographic variables are employed to a lesser extent.
With cross-tabulations and chi-square tests for association, we explored whether the use of segmentation
differs between companies with different objectives for
DM for selling products discriminate significantly
more on purchase amount ( p = 0.00). For companies
using DM to maintain relationships, this is also true
( p = 0.00), but they also discriminate on customer
profitability mor often ( p = 0.00). In line with this
result, these companies use segmentation for varying
treatment more frequently ( p = 0.00). We could not find
Table 3
Use of segmentation: purpose, criterion, and segmentation variables
Purpose of segmentation (n =160)
Percent
Selection
Varying treatment (e.g. pricing, product offer)
Varying timing
Varying models
90.0
64.4
42.5
26.9
Criterion variables (n =160)
Percent
Response rate
Purchase amount
Profitability
Creditworthiness
87.4
61.6
42.8
6.9
Segmentation variables (n =160)
Percent
Recency
Purchase Amount
Frequency
Response
Lifestyle information
Socio-demographic information
58.1
32.1
48.1
55.6
28.1
34.4
any significant differences for companies disseminating information with DM. However, our results show
that companies attracting customers with DM are more
likely to use segmentation ( p = 0.04), and that their
purpose of segmentation is more likely to be the
selection of target customers ( p = 0.01).
3.3. Use of predictive modeling
Almost half of the respondents report that they
predict the responses to their marketing activities. We
asked two specific questions with regard to response
modeling.
Are tests performed on random samples of the
customer base for the purpose of fitting response
models?
Which criterion variable is predicted?
Selecting random samples of the customer base for
testing purposes can be costly. However, almost 71%
of the respondents who fit predictive models report
testing for the purpose of generating a sample for
model building. Nearly all of the companies that
model attempt to predict primary response. Purchase
quantity or donations are predicted to a lesser extent
P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
475
3.4. Employed statistical techniques
Table 4
Use of predictive modeling
Predict. . .(n=110)
Percent
Primary response
Purchase amount
Payments
Rejects
98.2
43.6
2.7
3.6
(Table 4) [12]. Very few companies estimate secondary response such as payment or reject. Just as we
examined differences in the use of segmentation
between companies with different DM objectives,
we explored whether the use of predictive modeling
is different between companies with various DM
objectives. However, the analysis reveals no significant differences in the latter regard.
In our questions on the employed statistical techniques, we included those techniques that are cited in
the literature as being effective. Despite the fact that
literature advocates more sophisticated techniques
[18], cross-tabulation is the most widely utilized
method followed by RFM analysis (Fig. 1). Although
linear regression performs worse than CHAID and
logit or probit models [18], it is the third most popular
technique. CHAID or CART is employed by approximately 16% of the respondents employing segmentation and/or modeling, while logit or probit models
are used less. As Bult and Wansbeek [6] report that
CHAID does not predict as well as probit regression,
it is surprising to find that CHAID is also used for
predictive modeling purposes. Results of discriminant
analysis are not reliable in the case of low response
Fig. 1. Use of different statistical methods for segmentation and predictive modeling. The differences in sample sizes in Tables 4 and 5 and this
figure are the result of firms leaving the entire section on modeling and segmentation techniques blank. The lack of response in these sections
might be due to secrecy of the firms, or due to the fact that no techniques are used at all to develop segmentation rules. Since we cannot know
the motive behind the skipping of this part of the questionnaire, it was decided to omit these respondents from this section of the analysis.
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P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
rates [28], common to DBM. Hence, the low adoption
of this technique is not surprising. Zahavi and Levin
[35] report that neural networks perform worse than
logit or probit models. In practice, we only find a few
companies using neural networks. Probably, this is
due to the mentioned disappointing performance, but
also the black-box character and the low explanatory
power of neural networks might be an explanation
[30]. A few companies also use genetic algorithms.
Many respondents reported being unfamiliar with
logit/probit models, neural networks, and genetic
algorithms. It is interesting to note that the ranking
of techniques is the same for both segmentation and
predictive modeling, with the exception of factor and
cluster analysis, which only appear in the section on
segmentation techniques. While factor analysis and
cluster analysis can be employed as exploratory or
preparatory analyses for predictive modeling, their
outcomes do not directly yield response predictions.
They are performed for segmentation by approximately one quarter of the companies.
Of companies reporting the utilization of segmentation and predictive modeling, 30.6% and 35.5%,
respectively, indicate no method. A number of these
respondents used the fill-in line for the segmentation
and modeling technique questions to write in ‘‘gut
feeling’’ or ‘‘experience.’’ Despite the increasing availability of data and computer power in the last two
decades, segmentation and selection are still often
performed on the basis of intuition by a large group
of companies [5,p,17].
3.5. Company characteristics and modeling
We continue with a discussion and empirical
examination of the relationship between company
characteristics and the use of predictive modeling
and segmentation techniques. The use of these techniques is justified if the expected benefits exceed the
expected costs. We note that the expected benefits of
the models depend on the decision type and context
[10]. Increased expected benefits with regard to
segmentation and modeling in DBM can be found
in more efficient targeting. Expected costs of modeling and segmentation models are comprised of initial
development costs, maintenance costs, costs inherent
to model use, and costs of marketing data. The trade
off between costs and benefits varies with the number
of times a model is used [15,Chapter 20]. In a DM
environment, the number of applications for which a
model can be used is related to the frequency of direct
contacts. If a firm can reuse a model for more
applications, the total costs will rise less rapidly.
Hence, we expect that larger companies using DM
instruments more frequently will have lower incremental modeling costs. Moreover, these large companies benefit from economies of scale to invest in these
models [3,32]. We also expect that the benefits of
DBM models are related to the size of the customer
database and the years of experience in DM. For
companies with a larger customer database, more
efficient modeling will result in absolute larger
increases in profitably. Likewise, firms exclusively
utilizing the direct channel can expect greater gains in
profit from modeling than those utilizing both direct
and indirect channels. Experience also influences the
use of models, as companies new to DBM will not
assign modeling and segmentation a first priority.
Based on the above expectations, we estimate three
models to explore the relationship between modeling
and firm characteristics. In these models, we relate (i)
use of segmentation, (ii) use of predictive modeling,
and (iii) level of sophistication of statistical models to
the following firm characteristics: company size
(number of employees), frequency of DM contacts,
database size, and years of experience in DM. For
channel type and frequency of DM, dummy variables
are employed. The classes defined for company size,
database size, and number of years of DM experience
are replaced with midpoints of these classes for all
analyses.
We employ logistic regression to model the probability of use of segmentation and predictive modeling.
The second and third columns of Table 5 show the
results of the two regression models. The chi-square
statistic indicates that the model predicting incidence of
segmentation is not significant ( p = 0.39). Thus, the
company characteristics included in the questionnaire
cannot explain the incidence of segmentation in DBM.
The logistic model explaining predictive modeling is
significant ( p <0.01). Two significant predictors of
predictive modeling are the number of customers in
the database ( p <0.01) and the exclusive use of a direct
channel of distribution ( p <0.05). Other significant
( p <0.10) predictors are company size, years of experience in DBM, and the frequency of DM activities.
P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
Table 5
Model results for the effect of company characteristics on the use of
segmentation, predictive modeling, and statistical techniques
Variables
Segmentation Modeling
(n = 201)1,2,3 (n = 201)1,2,3
Company size
Database size
Years of
experience
in DBM
Direct channel only
Both channels
Frequency DM
> 1 per week
1 per week
1 – 3 per month
1 – 2 per quarter
Intercept 1
Intercept 2
4.5210
3.0410
0.005
Chi-square/LR
statistic
4
7
7.4210
5.2710
0.0292c
4c
7a
Sophistication
(n = 159)3,4,5
6.3410
2.0210
0.013
0.425
0.310
1.318b
0.471
0.281
0.152
0.542
0.426
0.358
0.329
0.016
N.A.
1.068c
0.114
0.774
0.294
1.925a
N.A.
0.590c
1.229b
0.940a
0.367
0.143
0.840b
9.50
50.56a
35.92a
4b
7b
1
Twenty-seven cases were listwise deleted because of missing
values in independent variables.
2
Estimated with logistic regression.
3 a
Parameter significant at 0.01 level; bparameter significant at
0.05 level; cparameter significant at 0.1 level.
4
Sample restricted to companies that segment and/or model.
5
Estimated with ordered regression in E-views.
The objective of the third model is to explain the
level of statistical sophistication among companies.
The companies included in this model are restricted to
only those that perform segmentation and/or predic-
477
tive modeling (n = 159). Within these companies, we
distinguish three groups of users: those who do not
use models (29%), those employing only the simple
models RFM or cross-tabulations (23%), and those
using more complex models such as regression analysis, CHAID, etc. (48%). It should be noted that the
first group is comprised mainly of companies indicating experience and gut feeling as techniques. Some
companies report using both simple and complex
models, presumably employing the simpler models
for exploratory analysis, then the more complex for
the final model. The firms are categorized by the
highest level of sophistication of the models they use.
This classification of techniques portrays the progression from intuition to sophisticated modeling. RFM
and cross-tabulations can be performed without statistical know-how or a statistical computer package.
Those techniques we call complex require both statistical software and a minimum level of statistical
understanding. We consider the modeling sophistication classification to be ordinally scaled. Therefore,
ordered regression analysis is an appropriate tool to
investigate the impact of firm characteristics on the
level of modeling [17]. The fourth column of Table 5
shows that three firm characteristics significantly
affect the level of sophistication of DBM modeling
and segmentation in companies. Both company size
and database size are positive predictors of sophistication ( p <0.05). The frequency of DM activities is
overall a positive predictor of sophistication.
Table 6
The subjective performance of database analysis methods
Mean score of stated performance of database analysis methods
Total sample (n = 228)
Segmentation (N = 228)
Apply
Do not apply
Predictive modeling (N = 228)
Apply
Do not apply
Sophistication (n = 172)
No techniques
Simple techniques
Sophisticated techniques
We are able to have better results with our
DM campaigns by using database analysis
tools (1= totally disagree, 5 = totally agree)
We are satisfied about the response
percentages of our DM campaigns
(1= totally disagree, 5 = totally agree)
3.90
3.07
4.01
3.61
3.17
2.82
4.23
3.58
3.17
2.97
3.80
3.97
4.22
3.15
3.08
3.15
Numbers in bold denote significant differences in mean values according to t-test or F-test.
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P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
3.6. Performance of analysis
Because the literature suggests that more complex
models outperform simpler ones (e.g., Ref. [5]), we
also question whether companies using the more
sophisticated models believe that they attain better
results by using them. We gave the respondents two
Likert-type statements on which they could indicate
their opinion on a 5-point scale ranging from totally
agree to totally disagree. The mean scores indicate that
the companies attribute better performance to their
analysis (3.9), but they still are not completely satisfied
with the results (3.07) (see Table 6). With regard to
segmentation, companies applying segmentation indicate a significantly better performance (4.01 vs. 3.61;
p = 0.01) and they are more satisfied with their results
(3.17 vs. 2.82; p = 0.02). Modelers have a significantly
better performance than non-modelers (4.23 vs. 3.58;
p = 0.00). They also appear more satisfied (3.17 vs.
2.97), although the latter result is not significant
( p = 0.14). Finally, in line with results in the literature,
we find that companies using more sophisticated
techniques indicate a significantly better performance
( p = 0.04). Note that this performance increases per
sophistication level. In spite of the perceived higher
performance, the sophisticated modelers are not significantly more satisfied with the results of their
campaigns ( p = 0.92). Hence, it seems that they seek
still better models.
3.7. Research issues
We ended the survey with a question to the
respondents as to which issues they believe require
further research, from their point of view as practitioners. Answers to this question can be used to guide
further scientific research that bridges the gap
between academic research and business practice.
We have selected issues from a review of the literature in the questionnaire development phase. The
most prevalent research issues are the role of DBM
in an Internet environment and the long-term effect
of DM campaigns (see Table 7). The importance of
the latter is also reflected in the interest for topics
such as influencing the lifetime value of customers
and the calculation of lifetime value. It is remarkable
that although 42.7% of the respondents report irritation to be an important issue, only 25.6% state that
Table 7
Important issues for further research from a practitioners’
perspective (N = 228)
Issue
Percent
Issue
Percent
Internet and DBM
Long-term effect
of DM offers
Irritation from
DM offers
Segmentation
Modeling primary
response
Calculating LTV
61.0
45.6
Influencing LTV
Offer segmentation
35.1
34.2
42.5
Modeling response
and amount
Privacy in DBM
Modeling secondary
response
Neural networks
29.8
36.8
36.4
35.7
25.4
15.4
7.0
privacy in DBM is an issue that calls for more research attention.
4. Conclusion
In this paper, we presented a research project that
studies how companies practice DBM. This is of
particular interest now that the growing interest in
CRM has resulted in an increasing importance of
databases in the marketing strategy of firms. We
investigated the contents of the customer database
and the use of external data. The results show that
although the large majority of companies store transaction type data, socio-demographic data and attitudinal data are stored only limitedly. In line with the
literature on conjoint analysis and UPC-scanner data
(e.g., Refs. [4,33]), we have investigated the commercial use of segmentation and predictive modeling
techniques in DBM. The most important conclusions
are the following. First, although the majority of the
companies perform segmentation, predictive modeling is used to a lesser extent. Second, few managers
use the models and insights generated by scientific
research. The statistical techniques employed by most
are still relatively simple. Many companies report that
they base their target selections on intuition and ‘‘gut
feeling’’, thereby using simple heuristics, such as
‘‘mail all customers, who recently purchased product
X’’, or ‘‘have an income above Y’’. The fact that models and insights generated by research are still limitedly used by managers is an important finding of our
research. It also has implications for the scientific
community. In order to further disseminate the developed models, the scientific community may wish to
P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
take specific steps, such as presenting research at
practitioner conferences. Moreover, as CRM and
DBM are recent developments in marketing and have
not widely gained attention in the curricula of marketing programs at business schools, there is a need to
develop marketing courses on CRM and DBM focusing on the application of the considered techniques.
Third, the sophistication of these models depends on
company size, size of the database, and the contact
frequency. This result emphasizes that economies of
scale are important in applying DBM techniques.
Fourth, companies applying more sophisticated techniques appear to have a better performance than
companies not applying these techniques. Hence, the
utilization sophisticated models indeed seems to payoff from a practitioners’ perspective. However, despite
the improved performance, these companies still seek
techniques that will further improve results. Finally,
from a practitioners’ perspective, important research
issues concern the long-term impact of DM media,
LTV, and irritation effects of DM.
5. Research limitations and future research
This research has three limitations. First, we restrict
our study to companies in the business-to-consumer
market. Future research might also consider firms in
business-to-business markets. Second, our study is
limited to the Netherlands. However, due to the effect
of sharing of methods by multinationals, we expect
the differences to be smaller than mere population and
size of database would dictate. Future research could
replicate and extend this study in other European
countries as well as in the US. These multi-country
studies would enable one to make cross-country
comparisons. These comparisons would probably
offer interesting insights, such as which market characteristics (i.e., market size, use of DM) explain the
divergence in the use DBM techniques between
countries. Third, although we do not find any nonresponse bias, the use of a self-administered questionnaire might have led to self-selection effects. Besides,
the noted issues future research could consider the
research issues raised by practitioners. Three issues
are especially relevant from a scientific perspective.
First, the prediction of customer lifetime value needs
further attention in the literature. Recently, Rust et al.
479
[25] have stressed the importance of customer lifetime
value as a new performance measure. Despite this
importance, only a few studies have modeled customer lifetime value (e.g., Ref. [26]). Second, due to
increasing importance of Internet, new types of data,
such as click data, are collected. What we do not
know is the value of these data? Furthermore, models
and systems should be developed that fit into the
interactive nature of the Internet. These models are
perhaps not based on traditional DBM models. Third,
while there is a lot of knowledge on the long-term
impact of for example sales promotions (e.g., Ref.
[19]), the long-term impact of CRM instruments has
not been investigated. Future research should elaborate on this issue. Finally, there remains value in
research that investigates the effective use of customer
databases within customer relationship management.
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Peter C. Verhoef is a post-doctoral researcher affiliated with the Department of
Marketing and Organization of the School
of Economics at the Erasmus University
Rotterdam. He is also a member of Erasmus
Research Institute in Management (ERIM).
In 2001, he received his PhD in marketing
from the Erasmus University. In his dissertation, he investigated how companies can
affect the lifetime value of customers. His
research interests include customer relationship management, waiting times, and private labels. His work has
been or will be published in the Journal of Consumer Psychology,
Journal of Retailing, Journal of the Academy of Marketing Science,
Decision Support Systems, and various other journals.
Penny. N. Spring is a former Ph.D. student of University of
Groningen (The Netherlands), Department of Economics, Subdepartment Marketing and Marketing Research. She defended her
dissertation entitled ‘‘Statistical Methods in Database Marketing’’ in
October 2002. She is currently Data Science Director for Reader’s
Digest Europe. Her research has been published in the Journal of
Market Focused Management and the Journal of Targeting for
Measurement and Analysis in Marketing.
Janny C. Hoekstra received her PhD in
economics from the University of Groningen in 1987. From 1994, she held a parttime position as a Professor in Direct
Marketing at the Erasmus University Rotterdam, The Netherlands. As from June
2000, she holds this position at the University of Groningen. Her research interests
include the development of the marketing
concept, market orientation, customer lifetime value, direct marketing, and e-commerce. She published papers in among others Industrial Marketing
Management, the European Journal of Marketing, the Journal of
Direct Marketing, the Journal of Market-Focused Management, and
the Journal of Retailing.
P.C. Verhoef et al. / Decision Support Systems 34 (2002) 471–481
Peter S. H. Leeflang studied Econometrics
at the Erasmus University of Rotterdam. He
obtained his PhD in 1974. At present, he is
Professor of Marketing at the Department of
Economics, University of Groningen, The
Netherlands. He wrote several books and
published in the Journal of Marketing, the
Journal of Marketing Research, Management
Science, Applied Economics and the International Journal of Research in Marketing.
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