X minds discuss Y
A quote that floats around the Internet from time to time goes,
Great minds discuss ideas; average minds discuss events; small minds discuss people.
Now from time to time you see quotes on the Internet attributed to people that you wish said them, but alas they did not. For example, Abraham Lincoln did not really say, "Do not trust quotes you see on the Internet." This quote has almost as shaky a provenance. Like most places I have seen it, BrainyQuote attributes it to Eleanor Roosevelt. WikiQuote, however, has it firmly in Disputed territory.
Regardless of where it comes from, and heedless of the risk of seeming elitist, I think this lines up well to the big three social media networks. (If you think those are Facebook, LinkedIn and Twitter, you are off by one: I consider LinkedIn equivalent to Facebook, only for business not personal matters. So to me the big three are Facebook/LinkedIn, Twitter and Google+. That's my story and I'm sticking to it.)
Facebook is all about people. Who you went to school with, who you're related to, who you're dating, which artists you're a fan of. Twitter is a raw news feed. Only Google+ organizes itself by design around ideas (Communities) and finds you connections based on mutually interesting topics.
And while I don't consider myself a "great mind", those are definitely the ones I want to hang out with.
h/t to +Sakari Maaranen.