The 'Bank the Bonus' method is a strategy used when playing slot machines to increase the chances of leaving the casino with a profit. The idea is to divide your budget into separate vouchers (e.g., five vouchers of $100 each if your budget is $500) and play different machines with each voucher. You play until you either lose the voucher or hit a bonus game. Once you hit a bonus, you cash out and move on to the next machine, without continuing to play on the same machine, which statistically would lead to a loss over time.