2012 Report: $28 Billion Book Publishers Industry

http://www.heraldonline.com/2012/09/14/4263330/research-and-markets-2012-report.html

The US book publishing industry consists of about 2,800 companies with combined annual revenue of about $28 billion. Major companies include John Wiley & Sons, McGraw-Hill, Pearson, and Scholastic, as well as publishing units of large media companies such as HarperCollins (owned by News Corp); Random House (owned by Bertelsmann); and Simon & Schuster (owned by CBS). The industry is highly concentrated: the top 50 companies generate about 80 percent of revenue.
...The industry is capital-intensive: average annual revenue per worker is about $385,000... Textbooks and adult trade books each account for more than 25 percent of the market, professional books 23 percent, children's books 8 percent, and reference books 6 percent.
About 315,000 new books are published in the US every year, according to Bowker.