In an article, the LA Times looks at how publishers count books. Bookscan has taken some of the guesswork out, but not all. And publishers aren't above touting huge print runs as a measure of a book's success, even if 60% end up on a remainder table.
From the article:
Elsewhere, sales claims are harder to explain. HarperCollins has declined to comment on a disparity that was noted last week in Publishers Weekly for Vikram Seth's latest novel, "Two Lives." The publisher claimed sales of 20,000; Nielsen BookScan reported only 6,000 copies sold, according to the magazine.
"Before BookScan, within the book business any sales numbers were assumed to be inflated — or at least generously interpreted — until verified," said Michael Cader, who runs the influential Publishers Marketplace website. "The only question was by how much." In Cussler's case, the contested figures are enormous. But for struggling writers, who are lucky to sell several thousand copies of a first novel, the disclosure of how well a book performs may be irrelevant, and even harmful.
"Most books don't have anywhere near the financial success of movies, even unsuccessful movies," said Cathy Langer, chief buyer for the Tattered Cover Bookstore in Denver. "So if you look at sales figures, it's not a pretty picture. And when you get so obsessed with numbers, you lose the wonder and creativity that's basic to the book business."
Others suggest the real problem with revealing sales numbers is that publishers put out too many books — and the vast majority sell poorly. Greco estimated that more than 200,000 titles were published last year, which averages out to 22 new books every hour. This is in addition to about 3.5 million already in print.