You could extend this concept to anything. The last few years for my then girlfriend / now wife, I've often bought a couple different versions of the same item (last year, 3 different car radios; year before; 4 different outside lights; etc) knowing that she'll only keep one of the items (the item SHE has chosen to be the best for her), with the others being returned. When I bought my new car a few years ago, the Toyota dealer basically let me use the model I was interested in for the day. I immediately drove it to an Acura dealer to compare it side by side. I ended up buying the Toyota, but when I initially drove away with it, there was a 50% chance I'd be returning it, having bought the Acura.

Was is unethical for me to take the loan of the Toyota (as per this thread's analogy, depriving another person the chance to use it) knowing there was a 50% chance I wouldn't keep it? Christmas time, lots of items out of stock before the holiday, followed by lots of returns afterwards. Is it unethical to buy something knowing there's a good chance you won't use it? Commerce will stop.

I'm certainly guilty when it comes to FF awards. When I booked award tickets to Key West last year (for this year), I initially selected the desired outbound, and a dummy return date. Held that for a week until my desired return date was available, but no more outbound availability. Made two reservations, then had an agent combine then, stripping the 'inner' segments so I got the desired outbound and return flights (note - agent did say that's not always guaranteed to occur). Not the way I really enjoyed doing it, but working within their FF system, it was the best for me.

I believe USAirways only lets you hold award reservations for 1 day, and United 3 days (maybe have those numbers reversed), compared to 14 days for Delta (down from 30 a few years ago). I guess the goal is to try to restrict holding seats you really won't end up using. However, I'm not sure it's made the reservation process for those airlines any easier. That 1-3 day hold time for United might be great when you are looking for availability (not much on hold), but it you are trying to book a 2 wk trip to Hawaii or Australia, it becomes a real pain in the ___. Suddenly you can't find anything because you can never align your departure dates with your return dates. So perhaps ALL of those people taking one week or more trips to these destinations have to settle for at least one undesirable flight, because they can never reserve exactly what they want.

Jeff