An interesting wrinkle on this was the recent Presidential election in the US. Some of my contacts "Liked" Romney's or Paul Ryan's page (or both) Every 3rd or 5th day they were there when I looked at my feed "Romney is great" and your 3 friends liked this etc. My first reaction was "Wow, my friends are pretty hard core Romney fans if they're liking every new post he puts up on his page" So from endorsing him once they sent the message indirectly to their friends about 8 - 12 over a two month period that they're a supporter. That's probably a lot more in your friends' face with your political belief than most realize. It's like the guy at a BBQ who casually says "I think I'm voting for Obama" vs the friend whom every time you see them in the build up to the election wants to talk about their candidate and you're voting for him right?