Casinos often offer "free play" instead of cash for a prize because it encourages the winner to continue playing in the casino. When a player receives "free play," they are more likely to stay in the casino and use the credit to play additional games, which increases the casino's revenue.
The most obvious benefit of playing free online slots is that you don't have to spend any money. This means you can try a game out without risking your bankroll on something that you may not enjoy.
