Durham, N.C. — A Duke University student has found one of the last untapped markets for advertising – people on the toilet.

Bryan Silverman, a sophomore studying neuroscience, and his brother, Jordan, founded Star Toilet Paper about a year ago and are now rolling out rolls that contain ads, coupons and even QR codes that people can scan with their smartphones to redeem discounts.

"Our tag line is, 'Don't rush. Look before you flush,'" Bryan Silverman said Monday.

The company already has attracted more than 50 advertisers for the toilet paper, which they provide free to public venues, including The Blue Note Grille and Devine's in Durham and restrooms in upscale locales such as Westchester, N.Y., and Ann Arbor, Mich.

"Business owners kind of chuckle at first, but once you get down to the nitty-gritty and all the details, they say that really is a good idea," he said.

The brothers use recycled paper and vegetable oil-based inks for the ads, which they say makes it safe to use and flush and easy to read.

Now that they're on a roll, they are working at DUhatch, Duke's student business incubator, to expand.

"It's a place for them to both work and connect with experts to move their businesses forward," DUhatch director Larry Boyd said. "I hope the business succeeds, but more than anything, I know Bryan's going to learn a whole lot in the process of doing this."

Silverman said building Star Toilet Paper has been a great experience, and he believes the firm can eventually be No. 1 in the business most associated with No. 2.

"In the long term, we hope to be the toilet paper provider for every public venue across America," he said. "There's no way to go other than with ambition."