Just as Google wasn’t the first search engine, Facebook didn’t invent the social network, but rather improved upon it in such a way that it became the de facto standard. In 2004, when CEO Mark Zuckerberg created Facebook for fellow students at Harvard University, Friendster had been out for about a year. While Facebook was still finding its footing in 2005, MySpace became the largest social networking site. But Zuckerberg kept futzing with Facebook’s design. In 2006, he added a news feed, which let everyone on a network see when others changed their status update or relationship status, an innovation in “micro-blogging” that would spawn Twitter and redefine social networking. That may well have been the secret sauce that eventually brought Facebook to its current 350 million users. Though Facebook’s early attempts at advertising were clumsy (like Beacon, which notified other members when you bought something), marketers saw the value of a friend’s recommendation over straight-up advertising. By decade’s end, Facebook was at the forefront of the evolution of online advertising. —Brian Morrissey
