Does Google use social signals as a ranking factor? A lot of folks seem to think so. Are they wrong? Or is the answer a bit more complex?
"67.6 percent of all items were shared using Circles and 33.8 percent of items were shared publicly (these percentages add up to more than 100 percent since some users combined sharing options for posts)".
Via Antonino Militello, Robin Good, Herve Peitrequin