" The company’s most effective marketing tactic (besides making a great product) would never have been conceived or attempted by a pure marketing team. Instead, the engineers coded a set of tools that made it possible for every member to seamlessly cross-post his or her Airbnb listing on craigslist (because craigslist does not technically “allow” this, it was a fairly ingenious work-around). As a result, Airbnb—a tiny site—suddenly had free distribution on one of the most popular websites in the world. "
― Ryan Holiday , Growth Hacker Marketing: A Primer on the Future of PR, Marketing, and Advertising