Honestly speaking why would you play on unknown or new gambling site where you can play the same game on the existing gambling site without having a problem? One reason is that they offer something that the existing gambling site don't for instance a opening promotions like free bets and many more. Usually that's the only way they can get players and also not because the gambling site is new it cannot be trusted.
New gambling sites bring new games and promotions that will somehow make us experience something new. But at the end of the day, reputation will always be the number one factor that gamblers will surely stay in a certain gambling site. That’s why if these new sites have a lot of lapses, I don’t think gamblers will return to gamble again. But not all new sites are seen like that, some are just as good and reputable like old gambling sites do.