Here's the full story on that, as told by me and Bethany to the reporter:
BETHANY:
> Here's another example of real-world yootling: I worked late at the office yesterday and once all our beemergencies were dispatched, we had an auction over IM to see if Danny would come pick me up from the office or if I'd ride my bike / the bus home:
> [IM transcript where sealed bids are revealed to be 15 (Bethany) and 14 (me); we have a hipchat bot to facilitate this]
> So Danny came to fetch me, and I paid him 0 * 14
DANNY:
> To clarify "drive you halfway home" was my way of offering to make it a joint decision whether to drive her home. So I'd either drive her home and she'd pay me something or I'd not drive her and pay her something. That probably sounds impossibly weird. The advantage is that I can offer the favor and the auction makes sure it only happens if she values it more than it costs me. Ie, it's the quantified equivalent of "are you sure? don't you need to get to sleep yourself?" etc.
> Yootling to do her the favor is mathematically equivalent to doing her half the favor. Or you can think of it like this: I'm committing to either doing her the favor for less money than she values the favor, or to giving her an amount of money equal to how much she values the favor.
> Again, the real point is just to make sure the favor only happens if it's actually socially efficient -- if it's not more skin off my nose than the favor is actually worth to her.