Bookstore chains and online retailers accounted for more than half of all book units bought by adults 18 years old and older, according to figures compiled by PubTrack Consumer, a new service introduced by Bowker in 2007. Chain bookstores had the largest share at 33%, while sales through the Internet had a 21% share. The findings for the full year did not change significantly from a report issued late last year, which measured sales through the first nine months of 2007, although the Internet segment picked up one percentage point in the final quarter. Overall, the retail segment accounted for 61% of unit purchases, compared to 36% in the direct-to-consumer category.

Other notable findings included a rather healthy 12% share for the struggling book club segment, while the independent bookselling sector was found to have only a 3% market share. (An online survey by Fairfield Research, which categorized channels a bit differently than Bowker, found independents' market share at about 9%, with online retailers at 30%; see PW, Mar. 31).

Bowker began collecting information for PubTrack in early 2007 using an online weekly survey of consumers' buying habits that is completed by about 15,000 consumers weekly. The service can also track unit sales by genre; in 2007 the mystery/detective category was the most popular, with a 17% market share. Romance had the second largest share at 11% and PubTrack found that the Harlequin romance seriec was the most popular series for adults over 18. James Patterson's Alex Cross series was the second most popular, followed by Janet Evanovich's Stephanie Plum line, Harry Potter and J.D. Robb/Nora Roberts's In Death series.