Of course, not every online casino will use it to steal your personal information or compromise you in any way but it still can spam you with countless emails and ads. No free slots require emails to work: all games are available right from the web pages they’re located at, and you don’t have to give your name or any other personal information to continue;
Free online slots aren’t free because you watch ads - they’re just trial versions of games you might want to try for real money later. Therefore, you don’t have to struggle and break your way through dozens of annoying pop-ups to play. Like usual ads, pop-ups want you to misclick and visit the pages you don’t actually need - so it’s always better to choose another website to play instead of clicking at the cross button for the twentieth time;
Of course, every online casino wants more clients: though the company allows you to play slots for free, it’s not because it’s generous but mostly because it wants you to become more interested in other casino games presented on the website. Of course, you don’t have to register to play a slot for free: this is just a manipulation, so it’s better for you to leave the website and look for more free games. A good free slot game should make you want to register but not vice versa;
Casino games aren’t that big or complicated - and that’s why lots of popular services present thousands of them to choose from. You don’t have to download any additional software to play these games: it’s not only unnecessary but also potentially dangerous because sometimes you download things you don’t want to have on your computer.