"The username is a relic," writes Mat Honan. "Here's how to fix it."
This has probably happened to you: You hear about some cool new app or game or service, rush to sign up, and discover that another person has already snagged the username you wanted. It’s a bummer and a bad first impression for a new service. The username just wasn’t built to withstand what the Internet has become. It’s a vestige of an earlier era, when a large service had thousands of users. Today, despite the billions of people online, we’re still designing for the sparse old days
Honan points to Facebook as an example of a service that doesn't rely on usernames, but accepts a disconcerting price—"only the machines need to see [unique identifiers]". I like the fact that on Twitter, for example, a @username refers unambiguously to a particular person, and that the functions of these usernames on Twitter are explicit and predictable.
On Facebook, however, the same kind of identification is much vaguer, and built around things you don't really get to see after you've inaugurated it with that initial act of Friending or Liking. You write out a plain old name, for example, and it does a load of under-the-hood autocompletion and contextual black magic. You don't decide who you are talking to, or about: Facebook decides. Unique identification bounces off into a hall of mirrors, alternately exposing and concealing people in unpredictable ways. As the machine mostly gets it right, and it's convenient, it has an accessibility level that the dry technical @twitter usernames don't. But it's odd when you type a name--say, a place of birth that's not in Facebook's official list of places--and hitting the return key gives you an error message, or mysteriously does nothing at all. Unique identification, for all its faults, isn't being improved upon here: it's being substituted with something weirder and creepier, and far from the more humane, meatspace-style connections we'd like to see.