Selling printed back issues of magazines has always proved a challenge for publishers; now they are finding that digital subscriptions, which offer single issues, are a practical avenue. At Hearst Magazines, 30% of the single copies sold on tablets are back issues, according to president David Carey. Hearst sells digital editions of many of its titles including Cosmopolitan, Esquire and Popular Mechanics on the iPad; single issues represent 10% - 15% of its digital editions volume and back issues make up some 4% of the total. Carey calls back issues the “long tail” of digital editions… making our ‘back list’ more easily accessed by readers.” Bonnier has had a similar experience. Its Popular Science magazine back issues have accounted for 40% of the single digital copies sold this year. For Martha Stewart Omnimedia, titles Martha Stewart Living and Everyday Food report that 25% of their digital single copies sold on the iPad are back issues.