Last week when I was considering how to stimulate conversation around items that I want to share, I considered a number of solutions before settling on Posterous. Google Reader shared items does not presently permit discussion and the next obvious solution, FriendFeed, just doesn't feel right.
The more I've played with Posterous, the more I like it. But why? On the face of it, there's little difference between Posterous and Tumblr, which offers more "features". But I don't want "features, I want conversation, and for whatever reason, that's what the design of Posterous seems to promote, such as this conversation.
If I could bottle and sell the architecture of participation, I'd make a fortune. But I can't. All I can do is recognize it when I see it. And hope that they don't ruin it by adding too many "features".