This really isn’t a new thing. I mean, it’s interesting how many popular celebrities use fake accounts to boost their followings and what not, but the tactic itself has been around since at least the late 90s/early 00s.
It’s basically forum management 101 at this point; sign up with a bunch of fake names, talk to yourself for a couple months and hope the real members eventually start rolling in. You could even buy dedicated software for this at one point, if you wanted to import 500,000 posts worth of gibberish from Yahoo Answers or what not.
Still, you know what they say. Don’t trust numbers you see online.