Free advertising. Even if you just get your friends to add your app to try it out - that gets broadcast to all of their friends who look at the news feed (I'd guess that few people don't). And if any of their friends are bored and happen to try out your application, then it keeps rippling out.
The trick of course, is to build something compelling. The platform will only mature with time, and the really compelling applications - that aren't just profile-based applications, or aren't heavily rooted in a site off of Facebook - haven't been built yet.
Why create a facebook application now given that there are thousands out there already and facebook has created lots of restrictions preventing the viral growth that the earlier apps experienced. Even the new ones like the one released by Yahoo only have 5000 users.
It may have made sense in the beginning - Can anyone see any benefit of this now? or is it just hype ?
Lets think about it like this, what happed when Microsoft released an OS and restricted the App developers, gave them hell. Well they wrote a new OS right. So when facebook doesn't go to bed with the app developers .. ummm, I am just wonderin out loud.
traffic and service recognition with a very focused market group. facebook's valuations, as inflated as they may be, could hold some truth based on the market they have targeted themselves into.
The trick of course, is to build something compelling. The platform will only mature with time, and the really compelling applications - that aren't just profile-based applications, or aren't heavily rooted in a site off of Facebook - haven't been built yet.
That's where you come in :)