E-books’ share of total consumer spending on books fell to 12% in the third quarter of 2013, compared to 13% in the third quarter of 2012, according to new findings released by Bowker Market Research. The market share of trade paperbacks fell by two percentage points in the period, while hardcovers’ share fell to 34%, from 35%. The winner in the quarter was the mass market paperback format, whose share of spending rose to 8%, from 5% in last year’s third period, according to Bowker.

The shift in spending among formats proved to be a boon to large bookstore chains, whose share of book spending rose to 25% in the third quarter, up from 20% in the same period last year, while online retailers saw their share of spending fall by six percentage points, year over year. Mass merchandisers, another channel that sells lots of mass market paperbacks, picked up one point of market share in the period. The changes in unit sales among channels and formats generally followed the spending trends.

The third quarter shifts were in line with changes that Bowker reported in the first half of the year, when e-book sales growth slowed and bricks-and-mortar bookstores’ share of spending rallied compared to that of e-tailers. Bowker showed that the market share of e-books was 13% for the first nine months of 2013—the same level as in the first nine months of 2012. For the first six months of 2013, e-books’ share of spending was slightly higher, at 14%. The only other change in spending between the nine-month and six-month periods was a one-percentage-point increase in the market share of mass market paperbacks. In terms of channel, the two most notable shifts in the year-to-date period through September, as in the third quarter, were gains at bookstore chains and declines at online retailers.