No deposit bonuses allow free play and winnings without you needing to deposit any money (or even providing your financial information!).
No deposit bonuses are usually given as part of a welcome offer to new customers when they register. But some casinos also give no deposit offers as part of their VIP rewards program or during special promotions
Casinos offer no deposit bonuses as a way of attracting new customers. In New Jersey there are over 20 online casinos, and they're all competing with each other to get new customers onto their sites.
No deposit offers don't only attract new gamblers. They are also open to anyone who is a new customer at a casino.