Why do birthday specials usually only last one night?

 Why do birthday specials usually only last one night?I've noticed a lot of places do one birthday night, a birthday weekend, or one designated date each month.We decided to try something different nearby in Stafford:If your birthday is anytime in September, you get in free all month.You don't have to wait until your actual birthday, and you don't have to use it on one specific night.The idea was pretty simple - most people don't celebrate alone anyway, so why limit someone to one night?Bring your ID. Bring your people.Curious what people here think - would you actually use a birthday-month offer more than once, or would you still just pick one night?FireHorse Saloon
501 Murphy Rd, Stafford