A free spins bonus is a promotional offer intended to entice new players to sign up and, more importantly, to keep existing players engaged with the casino. The idea is that you get free spins to play in designated slots games (or sometimes other games) without having to invest your own money. The term āfreeā refers to the fact that you donāt have to spend any money to take advantage of a free spins bonusāthe casino gives you a certain amount of free spins and you get to keep any winnings you get (up to certain limits).