Stats on iAd for developers

Is there any one-time $1 cost that companies advertise? I can't think of one.

I would say that one-time $1 products are in almost all cases unadvertisable. It's an economically inefficient use of advertising space. The best case scenario when someone sees his ad is a payoff of $0.70. That's the ceiling for the value of the an ad impression, and in reality it's pretty much guaranteed to be far, far lower.

Compare that to, say, advertising a car, where the payoff of a conversion may be several thousand (in profit). Sure, the conversion rate won't be as high because it's so expensive, but the potential pay-off is so much higher that it doesn't matter.

The only ads I can see for products that cheap are consumables (like gum). There's a reason for that. Unless the ad space is seen by a niche that's incredibly likely to buy your product (yet for some reason not already own it), there are other companies that can get much more value out of that ad space, which means that there are companies willing to pay more for it than the revenue it will get you.