Join My Starbucks Rewards and you’ll get a postcard coupon for a free drink for your Birthday. Any drink, any size! You’ll have until the end of the next month to use your coupon. To sign-up you need to register a Starbucks gift card (doesn’t have to have a balance on it). I get Starbucks gift cards for FREE from Swagbucks. 
So does that mean you need an old gift card to get this bonus? Because sadly I do not have a card!