Dan Gershenson said
1 year, 5 months ago: Without question, the motherlode for me has been StumbleUpon. Not so much for consistency but when it hits, it’s like a jackpot in Vegas.
Facebook is very much up there for shareability too.
Google+, Twitter outpace LinkedIn. At least for me. It’s funny what you think is going to do the most referring but the data ends up surprising you. And the data doesn’t lie!