Stickiness

"For many teens, MySpace is the first asynchronous messaging system that they use regularly. Sure, they have emails but those are to communicate with parents/teachers/companies, not with friends. People check in daily to see what messages they get. This was starting to happen on Friendster, but server slowness killed this practice. This will make it quite tricky for teens to fully leave MySpace while their friends are still using it." I'd never considered this, but it's a powerful argument - as long as your peers are using the system, you're stuck using it. Of course, in the case of Myspace everybody is just going to drop it at the same moment, as soon as it isn't cool anymore :) But, not so for most software that has some other purpose than being cool...