On average, a casino can make up to 5p for every €1 wager on a slot featuring a 95% RTP. And also how much is profit for the online casino. These figures show how much money will be returned to players over time. There’s a pre-determined Return To Player figure, which can either be set by the software developer or the casino itself. This is thanks to those casino games which run on an RNG.
An online casino’s net wins are more or less guaranteed to be positive over the long run.