From the early days of the commercial web, one thing has been clear: photos are big on the Internet. All of us love photos. We love taking photos. We love sharing photos. They are the basic unit of digital emotion. Facebook understood this early on, and knew that when combined with its social graph, photos could be their one-way ticket to unending engagement and thus commercial success. Instagram was attacking Facebook’s Achilles’ heel — mobile photo sharing – so they bought the company, for a billion dollars. And in doing so, Facebook has pretty much won the war for mobile photo sharing.