I'm as frustrated as everyone else about dirty/deceptive advertising used by airlines, hotels, and car rental companies, but this particular promotion seems straightforward to me. A lot of frequent-flyer promotions have restrictions, but as long as they are spelled out completely and in a straight-forward manner, I don't have a problem with it.

The worst abuses, IMHO, are the bogus fees that companies attach to their advertised fares. I don't have a problem with the government taxes being separate, but too often the companies add their own fees in a deceptive way in order to be able to advertise something else altogether. (Examples: fuel surcharges, concession recovery charges, resort fees, etc.)