They have a kind of loose definition of what they call beta. Consider how long GMail was in "beta" when in reality it was pretty much a finished project. It's

They have a kind of loose definition of what they call beta. Consider how long GMail was in "beta" when in reality it was pretty much a finished project. It's true that the invite system worked for gmail, but it's a bit different because gmail still has fundamental value if you are on it and literally none of your friends are.