"The US book publishing industry consists of about 2,600 companies with combined annual revenue of about $25 billion. [COMPARISON: The Motion Picture Industry's annual revenue is approx $55 Billion] The industry is highly concentrated: the top 50 companies generate about 80 percent of revenue.
Publishers produce books for general reading (adult "trade" books); text, professional, technical, children's, and reference books. Trade books account for 25 percent of the market, textbooks 25 percent, and professional books 20 percent.
About 150,000 new books are published in the US every year; however, most are low-volume products. The number of books produced by major trade publishers and university presses is closer to 40,000."