The short answer is they don’t. Online casinos do not make money from free spins. Free rounds are like samples that companies give away to introduce new products and attract new customers. Casinos in the UK hand out spins to market their website and use them as a tool to attract new players who will then hopefully become loyal players and recommend their site to others. So, while they may not make money off the original offer, the casinos are banking on getting a good return on their investment in the long run by encouraging more people to register and play on their site and ultimately spend way more money than their original bonus rounds were worth. Even though online casinos in the UK do not make any money off free spins, this is still a cheaper way for them to attract players than traditional advertising. Free spins work very well in Scandinavian countries where players usually deposit their own cash after they have used all their rounds. This means that the online casino will gain in the long run. In Russia, Poland, and other Eastern European countries, free spins are not as effective. This means they don’t offer online casinos the same return on their investment. This is because many players simply sign-up, use their bonus rounds, and then leave the site. This difference in playing styles and response to incentives also explains why some online casinos will offer free spins with no deposit and others will only have bonuses requiring a deposit.