The problem is that nowadays everybody wants you to install their api. While this is easy in the beginning, in the end it becomes a pain in the #$%#.

You can install http://www.flurry.com/ analytics on your app and be able to know the conversion to installs even for every creative you have on every social network or even links you give offline.

Really helped me track every possible detail on app promotion and the best of all... It's free ;)
Cheers,
Angel