A sportsbook is an establishment that accepts bets on a variety of sporting events. In exchange, they pay winners an amount based on the likelihood of a result and retain the stakes of those who do not win. They also charge a fee known as the vig. This fee is a significant component of a sportsbook’s business model, and it helps them generate revenue and profits.

Online sportsbooks feature hundreds of betting markets on a wide range of popular sports. Some of the most common are football (NFL), basketball (NBA), baseball (MLB) and ice hockey (NHL). But there are also markets on tennis, golf, and MMA. In addition, most top-rated sportsbooks have numerous prop bets available. These bets cover everything from the outcome of a coin toss to how many assists a player will record during a game.

In order to attract new customers, top-rated sportsbooks offer a wide variety of welcome promotions. These can include free bets, deposit match bonuses, and first-bet insurance up to a certain amount. Some of these offers may even require a promo code. However, it is important to look beyond a sportsbook’s welcome bonus offer when selecting one.

Sportsbooks have a responsibility to promote responsible gambling and provide tools to help players limit their bets and avoid problem gambling. These tools include wager, loss and session limits, time-outs, and non-reversible self-exclusion. They also have hotlines and links to organizations that can help people with problem gambling issues.