Welcome to Faceville
Facebook population: 20 million+
For the first three years of its existence, Facebook was just another place for people to exchange pokes and throw sheep at each other. But after Facebook opened its platform to third-party app developers it became something much bigger. The 85 initial apps introduced at the F8 conference in May 2007 would grow to more than 500,000 in just a few years and allow Facebook to leapfrog MySpace, while social games like Farmville, Cityville, and Mafia Wars would turn Zynga into the world's most annoying entertainment powerhouse.
The Good: People over the age of 22 finally had a reason to sign up
The Bad: Your friends just shoveled 90 million tons of manure on Farmville