The fact that it isn't obvious for somebody is strange. After all this is how old software works in 99% of the times: you have to write something of useful for

The fact that it isn't obvious for somebody is strange. After all this is how old software works in 99% of the times: you have to write something of useful for individuals alone. Web applications are now much more collaborative, and things like digg/reddit/... are useless without a community, but when possible it's much better to actually use the fact that individuals obtain advantages using the system in order to create part of the collaborative value. As a side note, my feeling is that most of the time web applications that are useful for single individuals tend to be more solid in some way: to compete with gmail you have to design a great web mail, since gmail is already pretty good, and this is hard. To compete with a site where the value is mostly in the community a competitor may attach you in different ways and it is much more a matter of fashion that technology.