In the light of this thread I just remembered this piece of news from a year ago - a half-price sale of a game resulted in 3000% increase in sales.
<quote>
* 10% sale = 35% increase in sales (real dollars, not units shipped)
* 25% sale = 245% increase in sales
* 50% sale = 320% increase in sales
* 75% sale = 1470% increase in sales
</quote>
Some strings attached of course, not exactly the same product type, but still I suspect that those of you guys open to licensing experiments may find it quite interesting.