Sports Betting Bonuses Bonus. It’s one of the best words in the English language. And in the sportsbook world, it usually means more money just for funding your account. Bonuses have been a part of the online sportsbook industry since its inception – though they have changed over the years, the basic premise remains the same: give bettors a reward for placing their sports bets. The best sportsbook bonuses are the online version of casino comps – perks designed to draw in more business and keep existing bettors coming back.