Here are some of the uses I know of for NCV chips:

Match play on table games
Free Play at a special slot
Use for table game wagers without restriction (Win Cards, for example)
Use-it-and-lose-it. One play and they take the chip, win or lose. You keep winnings.

An interesting variation was the chips you got with your vacation package at Vegas World. They could be played at face value, or cashed at a lower value, also shown on the chip.

I put some NCV's on eBay yesterday. Auctions close next weekend. See the pic below and the link to the list of auctions.

DonL