Flurry iOS analytics: "the sale of virtual goods is overtaking advertising"

It will be interesting to see how virtual currencies evolve and compete with more traditional economies. There's an interesting Q&A on Quora about Facebook emerging as a global currency: http://www.quora.com/Does-Facebook-Credits-have-the-chance-t...

This is one of those "I'm not like most people" moments. I find advertising SO much less annoying than paying for nothing. If you had asked me if this model would have caught on a few years ago, I'd have laughed at you. Shows what I know!

Is the real dynamic here one of peer-pressured purchases? Or is it more subtle than that?