A deposit bonus bet is a promotional offer provided by online betting platforms to attract new customers or retain existing ones. When a user makes a deposit, the platform matches a percentage of that amount as bonus funds, which can be used for placing bets. This incentive allows bettors to explore various betting options with extra funds, enhancing their overall experience. However, it's essential to read the terms and conditions, as these bonuses often come with wagering requirements that must be met before any winnings can be withdrawn.