They dropped out of slot machines after so much coin in.
You took them to the slot club and traded for cash or gifts.
They were the fore runner to the slot card.
Players were rated by how many they cashed in.
FQ's held the patent on system. Also used it at their AC property, Atlantis.
FQ's licensed it to the RIO when they opened. Rio marketing Director came from the FQ's.

Golden Nugget had a similar system but it put out paper tickets.