Although we don’t like to think any online gaming sites might be illegitimate, it’s a good idea to review several sites before you begin playing. The key factor you want to ascertain is whether both practice and paying players have an equal chance at winning any jackpots. Have you heard about the so called 'svenska spel'? You wouldn't like those! Also, you don’t want to begin playing on a site that treats paying players differently than those who use the practice games because that might indicate the machines are set up to only accommodate those who pay.
Another thing you want to look at is the size of the payouts compared to how much money you invest. You want to choose sites that provide a fairly even distribution between what you spend and what a machine pays. Those sites whose machines pay out infrequently may have software in place that allows them to prevent the machines from paying or to only pay out to certain players.