You can already purchase Facebook credits for games and the like. It's just a matter of time before they transition that into something with a wider reach.

Facebook Credits don't count?

Not familiar with those....are they interchangeable for money?

I'd like to be able to easily send $5 to a friend via facebook, or 25 cents to the author of a blog post I enjoyed. Others have tried the micropayments, but it needs a heavyweight to really pull it off. Maybe facebook can buy a startup that has it nicely figured out technically, but can't get traction.

You buy them with real money, and can spend them within applications on Facebook. It's not usable for anything outside of Facebook, or directly sending stuff to your friends.

But it's still the beginnings of an entry into the market.