Public restrooms are a unique space where the public and personal intersect. As advertising venues, they allow brands to reach individuals in an intimate, unguarded setting, secluded -- for just a moment -- from the frenetic activity and endless ad clutter of the world beyond the stall. Bathrooms also offer the advantage of a captive audience, albeit one increasingly equipped with smartphones, raising the possibility of interactivity. There are also certain truths: If you go to the bathroom, you'll use toilet paper. That’s the thinking behind Star Toilet Paper (slogan: “Changing the Way People Do Their Business”), a start-up which distributes free toilet paper with ads on it to schools, businesses and other public or private institutions with public restrooms. Launched by college students in 2011, Star currently has deals with eight venues, including San Jose City College, a community college located in Silicon Valley with a student body of around 12,000.On the advertiser side, it has relationships with around 70 clients, mostly local advertisers, and is now courting national advertisers as well. According to co-founder Bryan Silverman, a junior at Duke University, the ad-supported toilet paper is customized for each institution and can carry a wide range of messages and formats, including ads incorporating QR codes and SMS codes, which “allow advertisers to marry this unique form of out-of-home advertising with mobile tracking.” One recent survey suggested that around 75% of U.S. adults use their smartphone in the bathroom, so it makes sense to put smartphone-enabled interactive media next to the toilet. On that note, Silverman said QR codes in Star’s interactive toilet paper ads generate a 0.3% interactivity rate, meaning that three QR codes out of a thousand lead to smartphone activation. That compares to an overall interactivity rate of around 0.1%-0.2% for QR codes in general. Silverman added that one advertiser reported a 71% increase in month-over-month sales after offering a discount via Star’s toilet paper ads.It’s no surprise that many schools and businesses would welcome any way to trim costs, including outsourcing toilet paper to an ad-supported media company. Alarming as it sounds, toilet paper is often viewed as a “nonessential” item during budget crunches. In 2010, Newark Mayor Cory Booker cut toilet paper in city offices in order to save money, and in 2011 New York City began rationing toilet paper in women’s restrooms at Coney Island. More recently, in June of this year, Chicago schools said they would have to begin rationing toilet paper in response to budget cuts imposed by Mayor Rahm Emanuel. While toilet paper is apparently a new medium, other ad-supported paper hygiene products aren’t completely unknown. AdPack, a Japanese company, distributes around four billion packs of free facial tissues a year in Japan, in packages carrying advertising, QR and SMS codes, and even free samples.