A new survey of 10,000 book consumers via the Internet found that 18 percent bought religious or spiritual books last year. More than two-thirds said they purchased fiction, according to preliminary results from Publishers Weekly’s survey. Among nonfiction works, “practical life” was the largest category—bought by 35 percent. One editor suggested that Rick Warren’s best-selling The Purpose-Driven Life helped explain the practical-book popularity. The next largest category, 28 percent, was Bibles.