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Electronic messaging services in Germany: A survey
TELEMATICS and INFORMATICS
Vol. 10, No. 4, pp. 391-396, 1993 Copyright © 1993 Pergamon Press Ltd. Printed in the USA 0736-5853/93 $6.00 + .00
ELECTRONIC MESSAGING SERVICES IN GERMANY: A SURVEY Matthias W. Stoetzer Abstract--Electronic messaging services like other types of Value Added Services are said to lag behind in their development in Germany. The paper provides a short description of the main commercial and non-commercial electronic messaging services that are available for private households and businesses in Germany. It shows that a rather broad range of E-mail and videotex systems exist. Since the passage of the Telecommunication Reform Law o f 1989 in Germany all kinds of new telecommunication services (value added services, enhanced services, data communication services) can be offered by any provider, including the state-owned telecommunications carrier, DBP Telekom. I Electronic messaging services as part o f these enhanced services consist o f different types o f electronic mail and information systems. Often these electronic messaging services also provide access to online databases and include online transaction services. With regard to these telecommunications services it is possible to distinguish external provided services on the one hand and inhouse solutions on the other. Two categories of externally provided information services exist: commercial and noncommercial offerings. The commercial offerings include telecommunication services that are provided on the market for profit. Noncommercial services lack this profit orientation; in general, they only try to cover their cost.
COMMERCIAL SERVICES For commercial services, at the moment, the DBP Telekom remains the most relevant supplier. Telekom offers two main electronic messaging services: A videotex system called Datex-J (Btx) and Telebox, an electronic mail system. The videotex system offers a variety o f telecommunication services, e.g., E-mail, file transfer and the use of numerous online databases. The most popular applications for private users are homebanking, railroad and airline reservation systems, an electronic telephone directory, electronic shopping and information databases, e.g., for computers, automobiles and the stock markets. For business users, Btx (Datex-J) offers the possibility to form closed user groups and provides a telecommunications network for the transmission of little volumes of data. Ending June 1993 Datex-J had about 419,000 subscribers. Table 1 shows the development of users since the introduction of videotex in 1983. The sharp rise o f nearly
Matthias W. Stoetzer is affiliated with Wissenschaftliches Institut f~r Kommunikationsdienste (WIK), Rathausplatz 2-4, D-53604 Bad Honnef i, Germany. 'Only basic voice telephony and the telecommunication network are still monopolies of DBP Telekom.
391
392
Matthias W. Stoetzer Table 1. The Development of Videotex. Year
Number of subscribers
1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993, March 1993, June
10.155 21.329 38.894 58.365 95.932 146.929 194.827 260.111 302,274 340.423 375.000 419.000
Source: DBP Telekom.
80,000 new subscribers in the first two quarters o f 1993 i s d u e to a new marketing concept, concentrating on users connecting their P C to the Videotex system. This marketing effort includes the free distribution of simple modems (1200 bit/s) and decoder software and a change of the brand name from Btx (Bildschirmtext) to DatexJ. The monthly charge for a subscriber amounts to only $5. In addition, the subscribers pay between one and four cent per minute and separately for the information (Danke 1993). For the customer the Datex-J system is an inexpensive way to gain access to information and messaging services. Telebox in contrast to Datex-J/Btx only offers a message handling and E-mail system. This service is based on the X.400 standard. It was established in 1984 and in June 1993 had nearly 6,700 mailboxes (Table 2). The monthly membership fee amounts to $29. Per minute, the customer has to pay at least 22 cents plus a charge depending on the volume o f the information transmitted. Due to its rather expensive tariff it has a very limited n u m b e r of u s e r s - m o r e than half of its boxes are inhouse connections o f the DBP Telekom -- and remains a service for professional business users. F r o m the point o f view o f DBP Telekom, these two services are not very successful to date. They are b o t h loosing money and have failed to reach the market penetration goals set when they were launched. Concerning Datex-J/Btx the idea that there is great scope for videotex-based information services to the residential sector, because the information can be displayed on domestic television sets proved to be wrong. More Table 2. The Development of Telebox. Year
Number of boxes
1984 1985 1986 1987 1988 1989 1990 1991 1992 1993, March 1993, June
360 630 890 1.090 1.320 2.090 2.810 3.340 5.360 6.110 6.690
Source: DBP Telekom.
Electronic messaging services in G e r m a n y
393
Table 3. Private Commercial E-mail Systems. Service Supplier Alcatel SEL AT&T BT Cable & Wireless CocoNet ComBox CompuServe Connect debis Deutsche Mailbox Deutsche Mailbox Saar-Lor-Lux GElS GeoNet GSI GTC HBB IBM INAS Info AG Infonet MAXDAT MCI Meganet Microsoft MSN Radio Austria Radio Schweiz RMI Rechenzentrum Buchhandel Telehaus M01heim Telehaus Nordhorn Unisource Wieske's Crew
Only E-mail
Enhanced Services X X X X
X X X X X X X X X X X X X
X X X X X X X X X X X X X X X X
Source: Kuehnapfel/Gerwin 1993, WlK.
than 80% of the new subscribers use their PC to get access to the videotex system. With the boost of new subscribers in 1993 the goal to break-even with the Datex-J service in 1995 is not totally out of reach. Besides DBP Telekom, more than thirty private companies provide commercial E-mail services in Germany. About 20 of these companies are specialized on messaging services, the other offer electronic mail services only as part of their value added and managed network services (Table 3). Five of the major information services suppliers are CompuServe, Connect, GeoNet, GTC and MAXDAT. Their number of customers varies from about 1,000 up to about 20,000. Many of these companies are only providing regional services, e.g., Telehaus Miilheim and Telehaus Nordhorn, or specialise on certain groups of customers, e.g., ComBox is a system for journalists and reporters. These messaging services very often include access to online database information. Suppliers of online databases on the other hand sometimes offer E-mail services. A good example of an integration of both types of information services is Rechenzentrum Buchhandel GmbH. It provides services for booksellers. These include databases of books available and E-mail services. The prices of these messaging services vary concerning the installation charge, the monthly fee, the volume of transmission and the usage time. In addition, the service
394
Matthias W. Stoetzer Table 4. E-mail Market Volume 1989-1992. Year
Turnover (mill. US-S)
1989 1990 1991 1992
18,1 35,0 67,6 150,0
Source: Scicon Networks 1989.
provider charges a monthly minimum and offer discounts. Because o f these very different pricing schemes comparisons are difficult. With regard to the total market volume of commercially provided external information services some estimations are available. Table 4 shows the development o f the German E-mail market volume from 1989 to 1992. These figures imply an annual growth rate of more than 90°70. Other very different estimations of the electronic messaging and information markets exist, but they agree that firstly, most o f the market volume falls to online database services and secondly, the annual rate of growth at least amounts to about 2007o.
NONCOMMERCIAL SERVICES As to noncommercial services certainly the most relevant system is the German research network, WIN (Wissenschaftsnetz). This telecommunication network is provided since 1990 by the German association for a research network, DFN (Deutsches Forschungsnetz). It is a packet-switched network based on the X.25 standard and provides a variety o f telecommunications services, especially for the academic and scientific communities. The WIN offers the infrastructure for higher protocols such as DECNET, SNA, T C P / I P , X.400 and so on. The services include gateways and relays to the EARN/Bitnet system, the Internet system and X.400 Message Handling Systems, thus linking the users to the research networks in Europe and the USA (DFN 1993). Furthermore, the WIN serves as an access to many national and European databases, e.g., E C H O (European Commission Host Organization) and offers file transmission possibilities, using the FTAM and F T P protocols. The' number o f research institutions and universities using the WIN has grown from over 200 in January 1991 to more than 400 at the beginning of 1993. The subscribers have to pay a fiat-rate tariff per year independent o f the amount of transmission, the distance and so on (about $9,900 for a 9.6 kbit/s connection). Compared to the prices o f other telecommunication services providing the same functionality, this pricing scheme, in general, turns out to be cheaper and does not involve any uncertainties as to the bill at the end of the year. For universities and other institutions this seems to be a very much appreciated pricing structure. The subscription to the WIN is not allowed fo~ the commercial transmission o f data between enterprises. Besides the DFN as an official attempt to promote the use of telecommunication services for the academic community, many private E-mail systems exist. These systems still concentrate on topics mainly relevant for "Computer Freaks". Therefore, t h e most widely used applications are the exchange o f information as to PCs and programming, the downloading o f shareware and public-domain software and computer games. For the last few years the networks also began to cover other areas o f interest like, e.g., chat lines and information as to astronomy, cooking, environmental protection, philosophy, and politics.
Electronic messaging services in Germany
395
These E-mail boxes are organized in networks using the same software, but due to many existing gateways they are for the most part linked together. For transmission of data they almost exclusively rely on the telephone network and modems. Market estimations count for at least 2,000 of private messaging systems, bulletin boards and E-mail boxes. The most relevant systems are FidoNet, the German part of the worldwide Fido Network with about 800 systems, Zerberus-Net (around 200 systems), MausNet (around 50 systems), AmNet (around 40 systems), MagicBox, SubNet and UseNet (Groenling 1992). To cover their cost some of these private electronic messaging systems are charging their users moderate prices. The tariffs vary from $2 to about $6 per month.
INHOUSE SOLUTIONS Besides these information services that with some qualifications are open to the public there exist many inhouse applications of electronic messaging and online-database systems. Most of the large German enterprises have their on internal E-mail solutions that go beyond local area networks. A prominent example is theair transport industry, where Deutsche Lufthansa runs an E-mail system connecting nearly all their establishments worldwide. Furthermore, the automobile manufacturers, e.g., Volkswagen and Daimler Benz, use electronic information systems and also the German chemical industry is part of the business community relying on large and sophisticated inhouse networks. The insurance companies in Germany belong to the early adopters of new telecommunications services. A representative investigation points out, that in 1992 about 28°7o of the insurance companies used (internal and external) electronic mail systems in comparison to nearly 10070 of the German banks and only 3% of the wholesale and retail enterprises (Stoetzer 1993). THE OUTLOOK In comparison with that in the USA, the use of electronic messaging services in Germany surely is still in its infancy. Nevertheless, at the beginning of the nineties a wide variety of applications by business, academic and private users on commercial and non-profit grounds exist. Concerning the professional use of information services it is necessary to distinguish online database and messaging services. The use of online databases by business customers will be influenced by CD-ROM based information supply. Certainly, CD systems will become a substitute for traditional online database services with the exception of real-time-information services. On the contrary, the use of electronic messaging systems by enterprises is claimed to be a most promising market. These very optimistic forecasts and studies need a cautious interpretation, considering that this development already took place in the eighties but at that time failed because of the emergence of telefax. In June 1993 in Germany about 1.25 million Fax-connections were registered in the official fax-directory. Besides these, several hundreds of thousands fax-machines are installed without registration in a public directory. As to the academic community E-mail and file transfer will become more popular during the coming years. Their use will spread from informatics and natural sciences to the social sciences. This reflects the increasing awareness of these services and the increasing knowledge as to the use of computers. The use of E-mail services by private households in order to communicate probably will be limited to a certain group of users. This group of people using their PC for the
396
Matthias W. Stoetzer
exchange of. private i n f o r m a t i o n and entertainment will increase o n l y with m o d e r a t e rates because the residential sector prefers to use m o r e simple t e l e c o m m u n i c a t i o n services (telefax, answering machines). As to the mass market for commercial i n f o r m a tion systems and databases, a market potential exists, considering the increase o f penetration rates o f P C s o f private households during the last years. In this area h o m e banking might b e c o m e an important application. But the representative household will carefully c o m p a r e benefits and costs o f different solutions. In this respect an alternative like p h o n e - b a n k i n g m a y turn out to be more cost effective. Therefore, electronic i n f o r m a t i o n services like Datex-J will only b e c o m e a success story in the residential sector if their price will be low e n o u g h .
REFERENCES Danke, E. (1993). Bildschirmtext (Btx). In F. Arnold (Ed.). Handbuch der Telekommunikation. K61n: Deutscher Wirtschaftsclienst. DFN (Deutsches Forschungsaetz) (1993). Verzeichnis der Anwender des Wissenschaftsnetzes 0,ViN) und der DFN-Dienste, No. 1I, March 1993. Groenling, D. (1992). Elektronische N~ichte, Die Welt der Mailboxen und Computernetze. Frankfurt a.M.: Fischer. Kuehnapfel, J. B., & Gerwin, I. (1993). E-mail- und Telefax-Mehrwertdienste, Ratingen: Eutelis Consult. Scicon Networks (1989). The market f o r value added services in Europe. London: Author. Stoetzer, M.W. (1993). Der Einsatz yon Mehrwertdiensten in bundesdeutschen Unternehmen. Eine empirishe Bestandsaufnahme. WlK Diskussionsbaitrag No. 116. Bad Honnef: Wissenschaftliches Institut ffir Kommunikationsdienste.
Vol. 10, No. 4, pp. 391-396, 1993 Copyright © 1993 Pergamon Press Ltd. Printed in the USA 0736-5853/93 $6.00 + .00
ELECTRONIC MESSAGING SERVICES IN GERMANY: A SURVEY Matthias W. Stoetzer Abstract--Electronic messaging services like other types of Value Added Services are said to lag behind in their development in Germany. The paper provides a short description of the main commercial and non-commercial electronic messaging services that are available for private households and businesses in Germany. It shows that a rather broad range of E-mail and videotex systems exist. Since the passage of the Telecommunication Reform Law o f 1989 in Germany all kinds of new telecommunication services (value added services, enhanced services, data communication services) can be offered by any provider, including the state-owned telecommunications carrier, DBP Telekom. I Electronic messaging services as part o f these enhanced services consist o f different types o f electronic mail and information systems. Often these electronic messaging services also provide access to online databases and include online transaction services. With regard to these telecommunications services it is possible to distinguish external provided services on the one hand and inhouse solutions on the other. Two categories of externally provided information services exist: commercial and noncommercial offerings. The commercial offerings include telecommunication services that are provided on the market for profit. Noncommercial services lack this profit orientation; in general, they only try to cover their cost.
COMMERCIAL SERVICES For commercial services, at the moment, the DBP Telekom remains the most relevant supplier. Telekom offers two main electronic messaging services: A videotex system called Datex-J (Btx) and Telebox, an electronic mail system. The videotex system offers a variety o f telecommunication services, e.g., E-mail, file transfer and the use of numerous online databases. The most popular applications for private users are homebanking, railroad and airline reservation systems, an electronic telephone directory, electronic shopping and information databases, e.g., for computers, automobiles and the stock markets. For business users, Btx (Datex-J) offers the possibility to form closed user groups and provides a telecommunications network for the transmission of little volumes of data. Ending June 1993 Datex-J had about 419,000 subscribers. Table 1 shows the development of users since the introduction of videotex in 1983. The sharp rise o f nearly
Matthias W. Stoetzer is affiliated with Wissenschaftliches Institut f~r Kommunikationsdienste (WIK), Rathausplatz 2-4, D-53604 Bad Honnef i, Germany. 'Only basic voice telephony and the telecommunication network are still monopolies of DBP Telekom.
391
392
Matthias W. Stoetzer Table 1. The Development of Videotex. Year
Number of subscribers
1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993, March 1993, June
10.155 21.329 38.894 58.365 95.932 146.929 194.827 260.111 302,274 340.423 375.000 419.000
Source: DBP Telekom.
80,000 new subscribers in the first two quarters o f 1993 i s d u e to a new marketing concept, concentrating on users connecting their P C to the Videotex system. This marketing effort includes the free distribution of simple modems (1200 bit/s) and decoder software and a change of the brand name from Btx (Bildschirmtext) to DatexJ. The monthly charge for a subscriber amounts to only $5. In addition, the subscribers pay between one and four cent per minute and separately for the information (Danke 1993). For the customer the Datex-J system is an inexpensive way to gain access to information and messaging services. Telebox in contrast to Datex-J/Btx only offers a message handling and E-mail system. This service is based on the X.400 standard. It was established in 1984 and in June 1993 had nearly 6,700 mailboxes (Table 2). The monthly membership fee amounts to $29. Per minute, the customer has to pay at least 22 cents plus a charge depending on the volume o f the information transmitted. Due to its rather expensive tariff it has a very limited n u m b e r of u s e r s - m o r e than half of its boxes are inhouse connections o f the DBP Telekom -- and remains a service for professional business users. F r o m the point o f view o f DBP Telekom, these two services are not very successful to date. They are b o t h loosing money and have failed to reach the market penetration goals set when they were launched. Concerning Datex-J/Btx the idea that there is great scope for videotex-based information services to the residential sector, because the information can be displayed on domestic television sets proved to be wrong. More Table 2. The Development of Telebox. Year
Number of boxes
1984 1985 1986 1987 1988 1989 1990 1991 1992 1993, March 1993, June
360 630 890 1.090 1.320 2.090 2.810 3.340 5.360 6.110 6.690
Source: DBP Telekom.
Electronic messaging services in G e r m a n y
393
Table 3. Private Commercial E-mail Systems. Service Supplier Alcatel SEL AT&T BT Cable & Wireless CocoNet ComBox CompuServe Connect debis Deutsche Mailbox Deutsche Mailbox Saar-Lor-Lux GElS GeoNet GSI GTC HBB IBM INAS Info AG Infonet MAXDAT MCI Meganet Microsoft MSN Radio Austria Radio Schweiz RMI Rechenzentrum Buchhandel Telehaus M01heim Telehaus Nordhorn Unisource Wieske's Crew
Only E-mail
Enhanced Services X X X X
X X X X X X X X X X X X X
X X X X X X X X X X X X X X X X
Source: Kuehnapfel/Gerwin 1993, WlK.
than 80% of the new subscribers use their PC to get access to the videotex system. With the boost of new subscribers in 1993 the goal to break-even with the Datex-J service in 1995 is not totally out of reach. Besides DBP Telekom, more than thirty private companies provide commercial E-mail services in Germany. About 20 of these companies are specialized on messaging services, the other offer electronic mail services only as part of their value added and managed network services (Table 3). Five of the major information services suppliers are CompuServe, Connect, GeoNet, GTC and MAXDAT. Their number of customers varies from about 1,000 up to about 20,000. Many of these companies are only providing regional services, e.g., Telehaus Miilheim and Telehaus Nordhorn, or specialise on certain groups of customers, e.g., ComBox is a system for journalists and reporters. These messaging services very often include access to online database information. Suppliers of online databases on the other hand sometimes offer E-mail services. A good example of an integration of both types of information services is Rechenzentrum Buchhandel GmbH. It provides services for booksellers. These include databases of books available and E-mail services. The prices of these messaging services vary concerning the installation charge, the monthly fee, the volume of transmission and the usage time. In addition, the service
394
Matthias W. Stoetzer Table 4. E-mail Market Volume 1989-1992. Year
Turnover (mill. US-S)
1989 1990 1991 1992
18,1 35,0 67,6 150,0
Source: Scicon Networks 1989.
provider charges a monthly minimum and offer discounts. Because o f these very different pricing schemes comparisons are difficult. With regard to the total market volume of commercially provided external information services some estimations are available. Table 4 shows the development o f the German E-mail market volume from 1989 to 1992. These figures imply an annual growth rate of more than 90°70. Other very different estimations of the electronic messaging and information markets exist, but they agree that firstly, most o f the market volume falls to online database services and secondly, the annual rate of growth at least amounts to about 2007o.
NONCOMMERCIAL SERVICES As to noncommercial services certainly the most relevant system is the German research network, WIN (Wissenschaftsnetz). This telecommunication network is provided since 1990 by the German association for a research network, DFN (Deutsches Forschungsnetz). It is a packet-switched network based on the X.25 standard and provides a variety o f telecommunications services, especially for the academic and scientific communities. The WIN offers the infrastructure for higher protocols such as DECNET, SNA, T C P / I P , X.400 and so on. The services include gateways and relays to the EARN/Bitnet system, the Internet system and X.400 Message Handling Systems, thus linking the users to the research networks in Europe and the USA (DFN 1993). Furthermore, the WIN serves as an access to many national and European databases, e.g., E C H O (European Commission Host Organization) and offers file transmission possibilities, using the FTAM and F T P protocols. The' number o f research institutions and universities using the WIN has grown from over 200 in January 1991 to more than 400 at the beginning of 1993. The subscribers have to pay a fiat-rate tariff per year independent o f the amount of transmission, the distance and so on (about $9,900 for a 9.6 kbit/s connection). Compared to the prices o f other telecommunication services providing the same functionality, this pricing scheme, in general, turns out to be cheaper and does not involve any uncertainties as to the bill at the end of the year. For universities and other institutions this seems to be a very much appreciated pricing structure. The subscription to the WIN is not allowed fo~ the commercial transmission o f data between enterprises. Besides the DFN as an official attempt to promote the use of telecommunication services for the academic community, many private E-mail systems exist. These systems still concentrate on topics mainly relevant for "Computer Freaks". Therefore, t h e most widely used applications are the exchange o f information as to PCs and programming, the downloading o f shareware and public-domain software and computer games. For the last few years the networks also began to cover other areas o f interest like, e.g., chat lines and information as to astronomy, cooking, environmental protection, philosophy, and politics.
Electronic messaging services in Germany
395
These E-mail boxes are organized in networks using the same software, but due to many existing gateways they are for the most part linked together. For transmission of data they almost exclusively rely on the telephone network and modems. Market estimations count for at least 2,000 of private messaging systems, bulletin boards and E-mail boxes. The most relevant systems are FidoNet, the German part of the worldwide Fido Network with about 800 systems, Zerberus-Net (around 200 systems), MausNet (around 50 systems), AmNet (around 40 systems), MagicBox, SubNet and UseNet (Groenling 1992). To cover their cost some of these private electronic messaging systems are charging their users moderate prices. The tariffs vary from $2 to about $6 per month.
INHOUSE SOLUTIONS Besides these information services that with some qualifications are open to the public there exist many inhouse applications of electronic messaging and online-database systems. Most of the large German enterprises have their on internal E-mail solutions that go beyond local area networks. A prominent example is theair transport industry, where Deutsche Lufthansa runs an E-mail system connecting nearly all their establishments worldwide. Furthermore, the automobile manufacturers, e.g., Volkswagen and Daimler Benz, use electronic information systems and also the German chemical industry is part of the business community relying on large and sophisticated inhouse networks. The insurance companies in Germany belong to the early adopters of new telecommunications services. A representative investigation points out, that in 1992 about 28°7o of the insurance companies used (internal and external) electronic mail systems in comparison to nearly 10070 of the German banks and only 3% of the wholesale and retail enterprises (Stoetzer 1993). THE OUTLOOK In comparison with that in the USA, the use of electronic messaging services in Germany surely is still in its infancy. Nevertheless, at the beginning of the nineties a wide variety of applications by business, academic and private users on commercial and non-profit grounds exist. Concerning the professional use of information services it is necessary to distinguish online database and messaging services. The use of online databases by business customers will be influenced by CD-ROM based information supply. Certainly, CD systems will become a substitute for traditional online database services with the exception of real-time-information services. On the contrary, the use of electronic messaging systems by enterprises is claimed to be a most promising market. These very optimistic forecasts and studies need a cautious interpretation, considering that this development already took place in the eighties but at that time failed because of the emergence of telefax. In June 1993 in Germany about 1.25 million Fax-connections were registered in the official fax-directory. Besides these, several hundreds of thousands fax-machines are installed without registration in a public directory. As to the academic community E-mail and file transfer will become more popular during the coming years. Their use will spread from informatics and natural sciences to the social sciences. This reflects the increasing awareness of these services and the increasing knowledge as to the use of computers. The use of E-mail services by private households in order to communicate probably will be limited to a certain group of users. This group of people using their PC for the
396
Matthias W. Stoetzer
exchange of. private i n f o r m a t i o n and entertainment will increase o n l y with m o d e r a t e rates because the residential sector prefers to use m o r e simple t e l e c o m m u n i c a t i o n services (telefax, answering machines). As to the mass market for commercial i n f o r m a tion systems and databases, a market potential exists, considering the increase o f penetration rates o f P C s o f private households during the last years. In this area h o m e banking might b e c o m e an important application. But the representative household will carefully c o m p a r e benefits and costs o f different solutions. In this respect an alternative like p h o n e - b a n k i n g m a y turn out to be more cost effective. Therefore, electronic i n f o r m a t i o n services like Datex-J will only b e c o m e a success story in the residential sector if their price will be low e n o u g h .
REFERENCES Danke, E. (1993). Bildschirmtext (Btx). In F. Arnold (Ed.). Handbuch der Telekommunikation. K61n: Deutscher Wirtschaftsclienst. DFN (Deutsches Forschungsaetz) (1993). Verzeichnis der Anwender des Wissenschaftsnetzes 0,ViN) und der DFN-Dienste, No. 1I, March 1993. Groenling, D. (1992). Elektronische N~ichte, Die Welt der Mailboxen und Computernetze. Frankfurt a.M.: Fischer. Kuehnapfel, J. B., & Gerwin, I. (1993). E-mail- und Telefax-Mehrwertdienste, Ratingen: Eutelis Consult. Scicon Networks (1989). The market f o r value added services in Europe. London: Author. Stoetzer, M.W. (1993). Der Einsatz yon Mehrwertdiensten in bundesdeutschen Unternehmen. Eine empirishe Bestandsaufnahme. WlK Diskussionsbaitrag No. 116. Bad Honnef: Wissenschaftliches Institut ffir Kommunikationsdienste.