Who's really making money from the marathon?

Vendors pack the Myrtle Beach Convention Center for the runners expo.

MYRTLE BEACH, S.C. (WPDE) - The two day expo at the convention center before the Myrtle Beach Marathon could be called a runner's paradise. Anything you might need for the race is available, from ways to symbolize completing a goal to keeping runners safe at night. One vendor is selling a new product.

"We're selling sport earphones that actually go in your outer ear and not your in your ear canal. So they're much more comfortable, and they're a lot safer for you as well. You can hear full ambient sound," explains Chad Stender.

The special earphones have only been on the market for two years, but runners' expos allow vendors a unique opportunity.

"You get the first hand reaction of your customer. They give you the pluses and minuses. We're able to tweak things, and we're able to see what works really well for us. We love the interaction. We love seeing the people," adds Stender.

It's the same for Sam Mordecai. "It's rewarding when you have people like your product and tell you that." At the booth where he's working, runners have chosen from a variety of t-shirts, magnets, and other accessories.

As running grows in popularity, so does the market to cater to their needs. Vendors go from event to event nearly every weekend. The more runners, the more profitable the trip.

"This is my fourth expo in a row, back to back weekends. They're pretty tiring. It's hard work. It's a lot of fun, and it brings in a good amount of money," says Mordecai. "We've been on our feet all day today."

City of Myrtle Beach Public Information Officer Mark Kruea says the direct economic impact of the event is $6 million.