[bmelton]

True, but the question isn't whether or not they can afford it, as there's obviously very little that they can't afford, but one of whether it makes sense.

I'm assuming their bean counters have decided on an acceptable user acquisition cost, and likely won't bid above that. If, for example, they're willing to spend $1 on that spot, and somebody else is willing to give them $20 for it, I'm pretty certain they'd sell it out in a flat second.