“… Between 2002 and 2008, annual sales had grown just 1.6 per cent, and profit margins were shrinking. Like other struggling businesses, publishers had slashed expenditures, laying off editors and publicists and taking fewer chances on unknown writers.”

~snip~

“Good publishers find and cultivate writers, some of whom do not initially have much commercial promise. They also give advances on royalties, without which most writers of nonfiction could not afford to research new books. The industry produces more than a hundred thousand books a year, seventy per cent of which will not earn back the money that their authors have been advanced; aside from returns, royalty advances are by far publishers’ biggest expense. Although critics argue that traditional book publishing takes too much money from authors, in reality the profits earned by the relatively small percentage of authors whose books make money essentially go to subsidizing less commercially successful writers. The system is inefficient, but it supports a class of professional writers, which might not otherwise exist.”
Publish or Perish. Can the iPad topple the Kindle, and save the book business? by Ken Auletta, The New Yorker, April 26, 2010

Hm.