E-books accounted for 22% of all book spending in the second quarter of 2012, only a one percentage point gain from the first quarter of the year, but up from 14% in the comparable period in 2011, according to new figures from Bowker Market Research. In the year-to-year comparison, the hardcover and trade paperback segments both lost two percentage points each to e-books, while mass market paperbacks’ share fell from 15% in the second quarter of 2011 to 12% in this year’s second period. (See our chart.)

With the fall of Borders and the growth of e-books, Amazon increased its market share of consumer book spending between the second quarter of 2011 and 2012, although its growth slowed between the first quarter of 2012 and the second period. Still, the e-tailer was easily the largest single channel for book purchases in the second quarter, with an 11 percentage-point lead over Barnes & Noble. B&N’s share of unit purchases fell by two percentage points between June 2011 and June 2012, most likely due to sluggish sales of print content through BN.com. Independent booksellers managed to hold their own in the period, maintaining a 6% share of units.

Aside from Amazon’s increase in market share in the June 2011–June 2012 period, the biggest channel shifts came in the “all other” and dedicated e-book and downloadable audio sites. (See our chart.) The 21% share of other units in June 2011 reflects sales of Borders, which had about an 8% share of the market in its last year of existence. One of the many reasons for the failure of Borders was the growth of e-books (and its lack of participation in that segment), and dedicated digital sites’ share of units rose from 1% in June 2011 to 6% in June 2012. After a huge increase in share in the first quarter of 2012 as consumers loaded up on digital content after the holidays, dedicated digital sites’ share of units remained flat between the first and second quarter. E-tailers that are part of this channel include Audible, as well as the Apple iBookstore and what is known now as Google Play. One sales channel that had been losing share at a rapid pace, book clubs, may have bottomed out. Its share of units held even in the June to June span.