My theory is they have (or would had) more revenue from in-game adverstising than subscription fees.
I don't know what kind of partnership they have with Ford, Kodak, Novotel, etc. but, for sure, they would get more money if they have more players online. So the clever move is remove the PO fees and get all PO-haters in.
It's a game where in-game advertisments fit perfectly in. And I'm very surprised they have so many partners in only two months. Even the advertisments are on actual JCDecaux's.
That's my guess.