Many American casinos offer free memberships in “slot clubs,” which return a fraction of the amount of money that is bet in the form of comps (complimentary food, drinks, hotel rooms, or merchandise), or sometimes as cash or a promise to pay cash at a later date. These clubs require that players use cards that are inserted into the slot machines, to allow the casinos to track the players’ “action” (how much each player bets and for how long), which is often used to establish levels of play that may make players eligible for additional comps. Comps or “cash back” from these clubs can make significant differences in the maximum theoretical returns when playing over long periods.
