I don't know if I understood it right at all, I mean if that is what you are talking about some small casinos offer faucet all the time (and big ones like stake and primedice as well) but no sportsbook I know of and all the faucets you get are quite small amount that is really just not worth the gambling if you are looking to make money, just entertainment and a taste of the real game that is it.
Looking at the post you specifically said "websites that offer free bonuses without deposit", what would be the bonus for? Bonus means "on top of something" , like you buy 5 bananas and get one extra for bonus but pay 5, something like that, what would be the "bonus" without depositing?