Sure, the website promises free trips to exotic shores and exciting cities, but looking into things, there are hardly any dates, and the additional charges make it almost not worth spending the miles. I feel like only business travelers feel the real benefit of air miles programmes (or super-rich leisure travelers who don't really need the bonuses of Gold Membership - "Free to those that can afford it, very expensive to those that can't..."). It's like the airline throws out scraps to those of us outside the tent, and these keep us coming back to the tent, but we're never really invited in.
I've found the best value for spending miles has been short connecting flights on partner airlines on domestic routes in the US. I can fly from New Orleans to Dallas or Miami for a pretty good rate. The next thing I spend them on are hotel nights, but again, these tend to be overrpriced, but the miles don't gain value the more you hold onto them, so I just feel like spending them sometimes. Probably rash, but the average/slightly above average amount that I travel doesn't push me into the self-sustaining benefit party of the upper membership levels.
It looks as though this is a universal problem, as examined by this feature in the LA Times. They seem to suggest looking beyond national carriers to smaller up and coming airlines - fine if you're doing a regular journey, but for those of us that are more random, what are the options beyond what we're already doing?