From Publishers Weekly:
Sales of adult fiction and nonfiction rose 9.6% in April at the publishers that report their results to AAP’s StatShot statistics program. Within the adult category, e-book sales rose 38% for the month, to $92 million. Sales of trade paperback were up 10%, and hardcover sales inched up 0.5%. Sales of mass market paperback fell 15.6%. In the children’s/young adult segment, sales in April increased 24.3% at reporting publishers driven by a 42.8% increase in hardcover sales. Sales of e-books rose 29%, to $7.5 million.
You can read the full article on Publishers Weekly here: Trade Sales Up in April