I assume they are just alternate currency inside the club, much like chips at a casino (except you can't cash them out for real money at the end of the night). Maybe they are sold at a discount to cash, maybe dancers prefer chips to carrying 10 chips instead of $1k in cash...
When (as here) someone forgets/fails to cash them in, the house makes a killing.
If you bet a $5 Match Play chip and win, you typically get the $5 MP chip + a $5 chip back. You keep the MP chip until you lose.
@Copper44 has some cool Match Plays from the D.