The next toss is a random roll. It is a Regulation 6A IRS rule. It makes it easier for dealers to handle chips versus loose coins and paper money. You probably won't treat chips the same way you'll treat real money. The cost to maintain a nickel machine is the same as other machines.
Casinos know that low rollers play nickel machines so the sooner they get their money, the better.
It is all in the discretion of the slot department manager on what each machine returns. The dealer shuffles more giving you more time to discuss blackjack strategy with friends. The table minimums are generally lower. Avoid keno at all costs. It is a losing proposition for the casino because of its large payout.