Kids get a free kids meal on their birthday. When you register you get a free kids hamburger meal for your child on their birthday and they can play fun educational games on their website.
From their site: If your child is under 13 years old, you can register them for the BK CrownTM/MC Birthday Club. That means when your child’s birthday is nearing, you’ll receive an email coupon for a free BK® Kids Hamburger Meal if your child’s account has been validated and you’ve requested to receive it on the child’s behalf.
