If it is a place with highly variable rates, yes. Las Vegas would be my prime example. I booked with the Flamingo once and then rebooked three or four times as the rates dropped. I always book a new reservation before canceling the old, just in case it does not go through.

I'm also checking daily to see if I can get a better deal for my trip to ANC Saturday.

If it is a business trip where we have pre-set rates I don't bother.