> Facebook doesn't need you to give your name to figure out who you are. They don't sell advertising based on your name.
Well, they do need your name to link and correlate it with other data sources (like address books uploaded by people, offline data sources like data brokers, etc.) and use that to show "better ads" and make more money. The value lies in identifying related information with attributes like name, age, sex, location, preferences, check-ins, etc.
> Also, I think it's unfair to pretend that real names don't make a difference. They're a big part of what makes Facebook different than MySpace, Twitter, or other social networks.
Nobody is pretending. There are millions of people, not just a few exceptions, who use their real names and still engage in horrible behavior on Facebook. It's a misconception that "real names" makes people behave better or brings in accountability. It doesn't for the ones who harass others. On the other hand, using a real name exposes people to plenty of abuse online, like getting their profiles reported and deactivated because of Facebook's nonsensical rules and utter lack of any consideration for users, while bullies just go around shutting down people. Facebook is a great tool to shut people down whom one may disagree with.
Reading EFF and other sites' articles on Facebook's "real name policy" and the later rechristened "authentic name policy" would show the dark side of using real names online.