Definitions for "Payout Percentage"
The amount of every wager put into a Slot machine that is given back to the customer as a win, or payout. If a machine is said to have a 98% payout percentage, then that means that 98 cents out of every dollar is given back to customers in payouts, while the two cents leftover is the casino's take.
This is the percentage of sales that are paid back out in prizes by the House. Online bingo normally payouts out at around 70%.
The threoretical average percentage of money taken in that a casino's slot machines pay back to players. The percentage does not mean that all of the casino's machines pay back that amount. It is an average. Some will pay more, some less.