Led by strong demand for Harry Potter and the Order of the Phoenix as well as increased sales of interactive and sound books, sales of children's books rose 11%, to $2.1 billion, according to figures compiled by Ipsos BookTrends. The sales increase was driven primarily by higher price points since units rose only 2.5%, to 465 million, Ipsos reported.

The minor gain in unit growth was largely due to a shrinking consumer base. According to Ipsos, the number of U.S. households that bought one book for someone under the age of 14 fell to 33% in 2003 from 35% in 2002. Children's book purchases did pick up in the second half of the year, led by the June release of Potter and a strong fourth quarter.