Interesting. In Spain first the state takes a cut from the moment a coin goes in, and from the remainder they're bound to return 65% of the money collected, minumum. The machines have a government-certified black box to perform this accounting.
Now, the law doesn't say anything about prize structure, and it's common knowledge that big prizes tend to appear within 10 plays when it's "cooled down", because machines increasingly shut big prizes down when they notice they have a compulsive player on them.
In online gambling the games are never (or virtually never) rigged. Online slots also almost always pay out 96% or more. You make less money in the long runig you do not let your players win, but I assume small places like bars do not like that volatility.
It is still pointless to put in $1 and expect to receive an average of 96 cents. If you like speculation with less gambling, try call option debit or credit spreads on stocks or ETFs with a low bid/ask spread. It’s more sophisticated, more skill based, and has a higher EV.
And if you get good at it or are already good at it, let me know.
Now, the law doesn't say anything about prize structure, and it's common knowledge that big prizes tend to appear within 10 plays when it's "cooled down", because machines increasingly shut big prizes down when they notice they have a compulsive player on them.