Frequent Gamer Miles?

As the discourse over the new economic implications of the MMO market grows, I guess it makes sense that the next step someone would posit is the gaming equivalent of frequent flier miles. In other words, according to this article on Makezine.com, in the not-too-distant future, we will have credit card companies offering purchase incentives for gamers, much as they do for other consumers, by offering them free playtime, virtual currency, or other digital rewards.

I find this line-blurring between actual money & virtual currency endlessly fascinating (even though I haven't yet found a good way to get rich quick at it), and the idea of Visa teaming up with Blizzard or the like to try & get gamers to spend more money on their credit cards makes so much sense that I can't believe it isn't happening already. of course, as you read this, some venture capatalist somewhere is already picking up his phone...