While "free to play, pay to upgrade" is a payment structure more and more online games are adopting, the continued success of Blizzard's World of Warcraft shows there's still life in the old-fashioned model of paying a flat monthly subscription fee.
That's not to say, however, that Blizzard haven't noticed the commercial appeal of microtransactions.
In an interview with Videogamer, Blizzard's Tom Chilton has said:
I certainly think it's possible that we could do some kind of micro-transaction stuff. Whether or not World of Warcraft ever goes the direction of, I guess like Anarchy Online has gone the direction of going free-to-play with micro-transactions. Whether we ever shift to a free-to-play model is really too hard to say at this point. Anything I say now could easily five years from now end up seeming like, oh my gosh, that was an incredibly dumb thing to say, how naive!
Hardly a firm statement of intent, but then, you don't stay top dog without keeping an eye on the competition.
Blizzard's Tom Chilton on the future of WoW [VideoGamer]