Earlier quoted context omitted.
Sliding off topic but I think that's more like 49% of pulls. The amount of time that it takes a slot machine to drive your odds of walking away richer down to hopeless levels is pretty short.
I have only played slots for a few hours, but my lifetime average is up ~3x and a few hundred dollars vs. what I put into the machines. So, I think they are set fairly close to break even as that's from a few dozen minor wins vs a single jackpot. Honestly, if every single time someone played for 3+ hours they where always down then fewer people would come back. That said, they probably set machines in very high traff…
(How many people do you suppose play lotteries week in week out never winning back a fraction of what they out in, but dreaming about and planning what they're gonna spend the $10,000,000 jackpot on?)