Two scenarios:

1. A free service that doesn't work, will make those desperate newbies to try the paid service instead (which in turn, will be scammed).
2. Their (those newbies) transactions might received confirmations (especially now, since transaction fees and backlog of unconfirmed transactions is a lot lesser) normally (being mined by an actual pool) and yet they tip him for something he didn't do in the first place (and that's to accelerate those transactions).