[tweetiepooh]

Remote access - some pubs had a switch/dial behind the bar to adjust payout (or the facility could be available)

The house always wins - on pure chance the odds are below the actual chance of winning and games with "skill" where you can win, if you do win you get asked to stop. On a machine with say 97% payout even if totally even at say £1 a bet. You put in £100 and play away - the machine likely doesn't actually payout cash it apply winnings to your credit. After 100 goes you now have 97 goes and so on. Since you can lose not every go will return your credit, you may have won 97 credits on the 100th go. That's still 97% payout. That means you 97 credits won't get you to the next 100th go with it's 97 payout, you need to add 3 more so it's cost you £103 to have 97 more goes and so on. The things are more complex than that and will take from you more for less. And are designed to keep making you add another £3. If they are taking £100 a go, do you have enough to hit the next payout(s) to cover losses?

These machines make lots if money - at one employer with a bar it was only the fruit machine that made money, that was used to keep bar prices down. Even the few that did play the machine lost enough to fund the bar.

As already said whatever the payout it's not always going to be you that gets the payout. And the duration of the best is so quick you can easily put your profits back in in short order.