The cannibalization of print by digital accelerated in 2011, with unit sales in the outlets tracked by Nielsen BookScan falling 8.9% with one week to go in the year. The drop in print sales was double that of 2010, when units fell 4.5%. The decline from 2010 to 2011 sped up in all major categories and formats, and the categories where digital sales are having the greatest impact on the sale of print books didn’t change—adult fiction and mass market paperback.

After falling 7.2% in 2010, unit sales of print adult fiction tumbled 17.7% last year, to just over 160 million units, by far the steepest drop of the four major categories as more and more consumers turned to e-books for their fiction fix. Similar to 2010, sales of adult nonfiction took much less of a hit in 2011 than fiction, with units off 3.1% compared to 1.9% in 2010. The difference in the rate of decline between adult fiction and nonfiction rose significantly between 2010, when the difference was about six percentage points, and 2011, when the spread was more than 14 percentage points.

The trend between fiction and nonfiction unit sales in the juvenile categories was similar to that for adult. In fact, juvenile nonfiction sales fell almost the same amount as adult nonfiction, while the decline in fiction, while higher, was nowhere near the drop posted by adult fiction.

In terms of format performance, the BookScan figures confirm the trends about the deterioration of mass market paperback sales seen in the monthly Association of American Publishers statistics (p. 9). At the outlets followed by BookScan, unit sales of mass market paperbacks plunged 23.4%, falling well below 100 million units last year. Since 2008, unit sales of mass market paperbacks have fallen by almost 60%.

The hardcover segment, which had only a 1.5% unit dip in 2010, saw its decline accelerate to 6.9% last year, suggesting that, when the final dollar sales are totaled, revenue decline will be greater than in 2010 due to the steeper drop of higher-priced hardcovers. The unit sales of trade paperbacks fell 5.9% last year, compared to a decline of 3.1% in 2010 and indicate that, at least in 2011, most consumers were still willing to wait, and pay for, trade paperback editions of frontlist titles.

Nielsen BookScan estimates that it captures about 75% of print book unit sales.

Total Unit Sales of Print Books, 2010, 2011

2010 2011 % Change
702,307,000 640,592,000 -8.9%

Unit Sales of Print Books by Category, 2010, 20113

2010 2011 % Change
Adult Nonfiction 271,518,000 263,030,000 -3.1%
Adult Fiction 194,775,000 160,336,000 -17.7
Juvenile Nonfiction 36,931,000 35,799,000 -3.0
Juvenile Fiction 151,116,000 143,316,000 -5.2

Unit Sales of Print Books by Format, 2010, 2011

2010 2011 % Change
Hardcover 176,335,000 164,106,0001 -6.9%
Trade Paperback 373,182,000 351,043,000 -5.9
Mass Market Paperback 107,373,000 82,243,000 -23.0
Audio 6,077,000 5,323,000 -12.4