The highly-anticipated red cup promotion at Starbucks is back.Every year, the coffee conglomerate celebrates the cold-weather season with a special deal offered to customers who place certain holiday-themed orders.

It is Red Cup Day at coffee giant Starbucks, an unofficial holiday for java fans who enjoy discounts and rewards. Here's how it works: Stop by a participating Starbucks store on Thursday and get a free, 16-ounce holiday-themed reusable red cup when you purchase one of the coffee chain's special seasonal drinks.

"Red Cup Day," a favorite Starbucks holiday tradition that offers customers free reusable cups, takes place this week -- but there's a catch.