How many times is a tape used, before it hits the dumpster?

I've seen some B&W store tapes and they might as well have used nothing, because they never refreshed the tapes and the image was horrible.

I'm sure a casino with all the hi-tech and the high quality, plus color, replaces the tapes after a certain number of cycles through the machine?

Just wondering how many times a tape is recorded, before it's deemed unreliable?