Consumerist.com reports that the recent rash of Starbucks “cheer chains” is a clever coupon promotion.

I particularly like the technical name for this style of campaign: viral marketing. Apparently, it’s something that the company has been experimenting with for a while, as shown in this 2006 AdRants article.

Here’s how viral marketing works: you plant a promotional concept that spreads among customers (like a virus), generating news stories from unsuspecting reporters. In all media accounts, deny any involvement in the promotion and voila, you’ve got yourself some free publicity with a feel-good story of spontaneous cheer.

Starbucks spokeswoman Tricia Moriarty said these “infectious” giving acts have been happening across the country — recently, there were all-day giving chains at Starbucks in Pittsburg and in Florida.

Infectious, eh?