I do. Not all collectors do. Value depends on whether another collector needs it or not. TCR does assign value to NCV chips issued in Nevada.

If you're asking whether they have value to you as a player, it depends on the type of promo chip. If you have a "play till you lose it" chip, it has approximately 100% of face value in play (actually value is face value - (game hold percent * face value). If you have a "one play only" chip and you play it on an (approximately) even money game, it has approx 50% of face value in play (again, value is reduced on a "one play" promo chip based on the hold percent of the game you play it on).

"One play only" promo chips never used to be found at Nevada casinos; often found at Gulf Coast casinos. Now you see them at a lot of Nevada places as the owners tighten things up and try to give away less, even to regular players. Few players know there is a difference. Complain to your Host. Ask for twice as many promo chips if they are "one play only"!