I think this is funny. Dave Besbris, Engineering Director of Google+ explains why they are so slow in giving out invites to G+:
As Engineering Director of Google+, I wanted to take a moment to explain why we’re growing the system slowly. First, we want to make sure our infrastructure scales so the service remains fast and reliable. Second, we want to ensure that bugs are fixed while there are still a relatively few people in the field trial.
Come on Dave, there is a number three reason and everybody knows it. Why not admit that you’re creating free buzz around the Google+ rollout by making the invites scarce. If this had no marketing angle to it why do all the pundits and ‘tech celebs’ get an invite first? I don’t think anyone would begrudge Google for attempting to create more interest by rolling the service out slowly, but at least admit it.