It’s all about The Circles. The way we can use & manage this feature — allowing for targeted posts, privacy controls and the ability to disable resharing — is the best thing about Google+.
Plus as you put it ‘users are, as a whole, so much more engaged’.
Who was it who said that Facebook is for people you went to school with while Twitter is for people you wish you went to school with? Well, this is Twitter on steroids. And unlike Facebook, you don’t wake up to posts telling you that so-&-so
wants to share a gold coin with you or that they just fertilized their ovum. I mean farm, FARM! ;)