What are the most popular web apps according to Friend Feed usage?

Does showing up the most on FriendFeed mean "winning"?

I use Pandora even more than I use Twitter -- I have it open all day long on many days. But I have a few stations I'm pretty happy with, and I don't update it much anymore, so it barely registers on my FriendFeed.

Trick question: does the fact that Digg registers more comments than Reddit mean it's better?