A few months ago fatwallet.com users were told, via a massive thread, that Target stores should honor an ad touting mp3 players at around 30% off, for iPods. There was even a product code that included the iPods.
I tried it at my local Target and was refused, saying that it applied to "lesser-priced" mp3 players. In every way, according to the letter of the ad, the iPod qualified, but they blundered in not realizing there would be a run on iPods. Many people were successful with this ploy however, with several reporting that they bought as many as a dozen iPods in one go, until a corporatewide directive put an end to the gold rush.
Hm... isn't that kind of an opposite experience from what this thread asked for? The other side of the coin, I guess. Where the greed of some resulted in the exclusion of others. A form of capitalism no doubt.
As for me, I ended up buying an iPod for about the same deal when the 40G photo went into closeout a few weeks later.