Ok... its a little bit of a stretch, but I've often wondered if an airline has ever intentionally "accidently" left a $0 fare in the system just to get publicity. Of course you couldn't do it with too many seats, but I've read articles in USAToday and other major media sources about other carriers having computer glitches that sold tickets for practically nothing, and the articles do a great job catching the readers attention and plugging the airline (for example, the article on DH highlights the fall fare sale). I wonder if any airline has ever looked into the amount of revenue lost vs. the amount of potential revenue brought in from the added exposure.