The meaning is direct: A bonus offered by the casino when a player is celebrating their day of birth. It may be offered on a single day or a certain period around the said day, e.g. birthday week or birthday month. The casino awards a birthday bonus on the date that a player inputs when signing up, even if that is not their actual birth date.
In the increasingly competitive casino industry, online casinos are always looking for ways to keep their customers. Bonuses are a key method used for this purpose. The most popular bonuses include welcome, weekly deposit bonuses. In a new emerging trend, more and more casinos are now embracing birthday bonuses as a way of rewarding their loyal customers.