Are tenant raffles/incentives legal?

[Jack Lee]

I was talking to a local investor recently and he mentioned that he gives $50 once in a while to his tenants that pay on time. He was clear that this was random and that tenants don't have to "buy a ticket" to enter this random drawing. Tenants are entered into this random drawing simply for paying rent on time. I was just wondering if this is legal because a lot of states have strict lottery/raffle laws.

Thanks