Surprisingly, Pinterest. Yes, Pinterest. That Pinterest, the visual bookmarking site that had its start with crafters. I joined in April of 2011 and not finding pins that strongly piqued my interests, I started pinning stuff that I was attracted to, namely kicks. Of my various Pinterest boards, my Kicks Pinboard is the most active with 573 pins and over 2600 followers.
That amount of followers easily eclipses any of my other social networks, Twitter, Instagram, Google+, and even Plurk (my favorite social networking underdog). So whatever magic and mojo Pinterest possess, I can attest to it.