Sweepstakes and social casino platforms have adopted the purchase mechanic using virtual coins rather than cash. Players buy feature rounds with gold coins that carry no monetary value, or with sweepstakes coins that can be redeemed for prizes in markets where the model is permitted. It is possible to play bonus buy slots online in this format from regions where real-money gambling is restricted, which explains the model’s rapid growth. The mathematics of the round are typically identical to the real-money version from the same studio.