And a deeper reality of social networks is becoming clear as the industry matures: People don’t have a problem with being members of a few social networks, as long as they all offer different experiences. Think of four of the most popular social networks: Facebook, Foursquare, LinkedIn and Twitter. They all fall into the broad social networking category, but each have extremely distinct characteristics. While Facebook is for general socializing, Foursquare is location-based, and LinkedIn for business. Twitter is in a space all its own, as a place for status updates among broad groups of people who wouldn’t necessarily qualify as Facebook friends. Each fulfills a different need.

When MySpace began to slide downhill, it was largely because Facebook did most of the things MySpace did in a smarter way. There simply wasn’t room — or need — for both of them. Theoretically that leaves room for a better Facebook, but, even if it’s being created by Google, that’s not a very reasonable aspiration. Not when Facebook has hundreds of millions more users than MySpace did at its peak. The mountain is just getting too high.