By Monday, more than 26 million Facebook users had given their profile pictures the rainbow treatment in support of the Supreme Court’s ruling on gay marriage. Along with the popular support among individuals, a significant number of corporations jumped on-board (or even led the bandwagon). America’s biggest corporations have recently been among the most ardent proponents of social change. That’s in part because of the executive-level leadership found in a new breed of young companies. But I’m convinced it’s also because of the impact that social media has in an age where corporations hear loud and clear opinions from their customers. Consider how quickly stores raced to pull the Confederate flag from their shelves. We’ll undoubtedly see a steady rise in the effectiveness of this new rainbow coalition of popular opinion and corporate influence. For now, Newsweek’s Emily Cadei takes a look at how corporate America propelled same-sex marriage.