President Obama makes a stop at Pleasant Pops in D.C. with daughters Malia (left) and Sasha during Small Business Saturday in 2015. (Mandel Ngan/AFP/Getty Images)

Small Business Saturday is this Saturday. It’s become a really, really big thing. How big?

The campaign began back in 2009 by American Express when the country, and small businesses in particular, was still recovering from the Great Recession. The plan was to offer incentives to get people shopping again (and of course use their AmEx cards) at local merchants. And then things exploded.

By 2015, the one-day event attracted 95 million shoppers who spent more than $16 billion, according to this blog entry from the cloud-based business telephone provider Grasshopper.com. Grasshopper also reported there were over 241,000 posts on social media that year and awareness grew to over 55 percent of U.S. consumers. Congress has designated a special national day to honor the event and most politicians now feel the need to take an obligatory photo making a purchase at a local merchant to show their support.

But isn’t it just a marketing gimmick invented by American Express? Not really, but according to Fortune’s Jeremy Quittner it’s definitely a marketing campaign.

The card payments company started the campaign by offering cardholders a $25 credit if they shopped at a small business. American Express scaled that back to $10 in 2013 and last year offered no financial incentives. You can’t really blame them–it’s not as if small businesses need the help anymore, with so many billions being purchased.

But the campaign continues. Instead of offering a credit to consumers American Express shifted its strategy and now provides marketing help for its merchants to capitalize on the big day. The company “never intended to perpetuate the cash reward forever,” said Brian Riley, a credit advisory director at Mercator Advisory Group in the Fortune report.

“In the first couple of years, the incentives got people to come in, but the ‘local-first’ movement has sunk in, and people get it now,” a bookshop owner told Fortune. He admits that stores like his aren’t as reliant on the incentives anymore–in fact, his San Francisco based shop experiences a 20 percent increase in sales on that day alone.