Would I use it for my startup? Probably not... because I've already made my own: http://www.lifelitup.com - it didn't take very long to make.

I do not have the viral parts, (invite 3 people) because as cabalamat said, it reminds me too much of Facebook Applications. I didn't want people spamming their friends.

Don't get me wrong, I think your service would be beneficial for sure, just make sure to include heaps of features, (i.e. no viralness) :-)