Are you a fan of Starbucks? America's favorite coffee chain is charging up its loyalty program with plans to double membership by the end of the year to nine million. Beginning in May, the world's largest coffee company says loyalty members will be able to earn points when they buy bags of Starbucks coffee at supermarkets. To get the points, members will have to go online and enter a code on the bag. The My Starbucks rewards program gives customers free drinks and food based on the number of points they earn.