Even as organic reach declines, Facebook's best day for engagement is Fridays

[youtube https://www.youtube.com/watch?v=w1cBvXIF6_A&w=620&h=315]

There's a cool post over at Buffer about surprising social media statistics, and while a few different things stand out -- for example, about 91 percent of your mentions on Twitter will likely come from a user with less than 500 followers (thus don't chase the big game, per se) -- there's …