Free spins are part and parcel of online casinos nowadays. The y can be integrated within a welcome bonus alongside your match i.e. 100% match up to $100 + 100 Free Spins, or offered as standalone promotions.
Either way, free spins bonuses are of great value. Outside of welcome bonuses, casinos will offer you free spins on random occasions, during holiday promotional periods, as part of loyalty scheme rewards, and so forth.