That's part of it. Some hotel programs have no blackout dates, for rooms at reasonable point levels. Almost all airline programs tightly restrict "saver" awards on many routes, forcing you to use double the nominal points.

Take an example -- a few weeks ago I needed (well . . .) to be in Atlantic City over the weekend (memo to self: horrible place). For a horrible place, it fills up on weekends, bigtime. I could not find a "real" (that is, Marina or Boardwalk, non-motel) hotel for under $299. But using Starwoods points, I got a large King room at the very nice Sheraton convention center for 7,000 points. Not only is that a third of the price of the cheapest airline ticket, it's a $300 value for $7k worth of spend. The best cashback card would have yielded me at most around $150.

As with all good deals, you need to monitor how good they are -- Hyatt, for instance, sent me an innocuous little e-mail recently about some program "enhancements" that will net out to move a good number of "okay" quality hotels into the "expensive" redemption level, and some "expensive" ones into "luxury."