Return on investment is (still) the social media marketer’s biggest challenge. For years marketers have tried to tie tweets to sales, attribute Facebook to finance, and get dollars out of Instagram ads. But the true return of social media isn’t so cleanly defined. And there is a simple reason you shouldn’t chain your social performance directly to dollar signs - people don’t use social that way. Facebook, Instagram, Twitter, Snapchat - these are, first and foremost, personal platforms.