Thin Reads Launches to Track E-Book Singles Market:  A new web-based e-book singles aggregator launched this week. Called Thin Reads  and started by Howard Polskin, who left his executive vice president  post at the MPA in December, it's a consumer-facing database of e-book  singles available from Amazon, Barnes & Noble and iBookstore. E-book  singles, defined as works of short fiction or non-fiction that are  between 5,000 and 25,000 words long, have been a burgeoning market, one  that has its fingers in magazine publishing as well. The Atlantic just formed a partnership with Longreads—and Hearst, Rodale and Condé Nast, among others, have all been selling e-books and e-singles for the last couple years.