 example is SMS. The technical solution and the user interface are far from perfect, but SMS fulfils an obvious need. In Sweden in 2001 more than one billion SMS messages were sent, despite a cost of 1:25-1:50 SEK per mail. Videophone, on the other hand, has been a potential service since the 1970s with little success SO far. It can be said that a successful service is an affordable service that fulfils a need. Yet, it is no guarantee of revenue or retention of customers. For the actors with an interface to the end user, a true understanding of the end-user needs, professional customer care and appropriate service level agreements are keys to retaining existing end users and to acquiring new ones. Thus, customer focus is more important than ever before. But the questions are: what is really needed from a human point of view, considering that the human being is roughly the same as it was thousands of years ago, and how fast can the perception of the end-user change? Other business sectors, such as the car industry, have no doubt been more successful than telecom here, although selling telecom services should not be very much different from selling a car, theoretically. Östen Mäkitalo at Telia Sonera in Sweden says that there is a need for considerably more research within this area. 'The behavioural research is lagging behind. The mobile terminal should become everyone's personal assistant. A simple use, with voice control and voice recognition, is an important interface feature. The assistant should primarily help us in common everyday tasks'. 'Life enhancement' is another way to describe this goal. Others express it like this: 'Take control over the electronic environment by using your mobile as a personal universal remote control'. Hopefully this book can shed some more light on the vast and crucial end-user area. 2.3 USER ANALYSIS AND SEGMENTATION 2.3.1 THE PRIVATE AREA ENVIRONMENT AND ITS END-USER CHARACTERISTICS AND SEGMENTS To be understandable, the basic needs should preferably be combined with a basic env