Customers who return to Starbucks with the custom cup, or any reusable cup, will receive a 10-cent discount on their order and Starbucks Rewards members can earn 25 stars when they bring back their reusable red cup for future orders.

Starbucks Red Cup Day has become an unofficial harbinger of the holiday season for fans of the coffee chain. Here's a look at what makes Red Cup Day special.

Holiday drink season has arrived with cafes and restaurants across the country now serving peppermint, gingerbread and cookie-flavored beverages in "red cups." Why it matters: Businesses are capitalizing on holiday cheer to create a buzz and drive sales.