The frequent fliers who flew too much
There is always going to be a subset of people who are adept at finding ways around promotions and special offers, or the systems meant to regulate them. In addition, most companies don't understand how customers will react to contests and special offers.For instance, when iTunes first launched, Pepsi had a promo that involved codes on the underside of 20oz plastic bottle caps that could grant free songs. Someone figured out that if you turned the bottle upside-down and at a certain angle before opening it, you could see the code and enter it into iTunes to determine if you got a free song. If the code was a dud, you could return the drink or sell it to someone else. Someone ended up putting the diagram on the Web. The promo ended not long afterwards.There are also folks who figure out extreme hacks that can result in truly oversized rewards. I call this the "crates of cheese" phenomenon, after an airline promotion I read about that awarded people x frequent flier miles for purchasing a package of cheese. The rate was way too generous, and the marketing people setting up the promotion never anticipated that people would literally go out to buy crates of cheese to get cut-rate flights.EDIT:Crates of cheese:http://consumerist.com/2006/11/buy-cheese-fly-for-free.htmlPepsi/iTunes:http://www.methodshop.com/gadgets/tutorials/hackpepsi/index....