Starbucks: FREE drink when you sign up for Starbucks Rewards emails Shared on October 16, 2014 This post may contain affiliate links which means I make a small commission if you make a purchase at no additional cost to you. See the disclosure policy for more information. Starbucks is offering a FREE drink when you join My Starbucks Rewards. Sign up to receive email rewards, and you’ll get a free drink. Easy, peasy. This post may contain affiliate links. See the disclosure policy for more information.