August was a tough month for the two main trade categories, as sales fell in both the adult books segment and the children's/young adult category. The AAP reported, in its monthly StatShot report that, compared to the same period last year, adult sales fell 11.3%, while children's/young adult fell 5.8%.

The decline in adult titles was due to steep drops in sales of mass market paperbacks (down 45.0%) and hardcovers (down 28.7%). Sales of downloadable audiobooks, though, were up. Downloadable jumped 47.4% in the month, offsetting a 24.2% decline in physical audiobook sales. E-book sales were also down, falling 3.7%.

Despite the drop in August, sales of adult books were up 1.8% for the first eight months of 2015, led by a 13.9% jump in trade paperback sales in the period and a 41.9% increase in downloadable audio sales. Mass market paperback, hardcover and e-book sales were all down in the first eight months of the year, with e-book sales off 4.5%.

In children's/young adult, the 5.8% decline in August was due to declines in three of the four major segments: e-books, board books and hardcovers. E-book sales plunged 43.2%, board book sales were off 26.8%, and hardcover sales fell 15.7%. Only paperback sales rose in the month, up 16.5%.

The pattern in August in children's/young adult was reflected in the results for the first eight months of the year. For this period paperback sales in children's/young adult were up 9.8%. Sales in the other formats in the category were down, with e-book sales declining 44.5%.

Sales in AAP's StatShot program are based on reports from 1,206 publishers.