When e-books first began to make meaningful inroads in publishing in 2009–2010, a number of executives predicted they would become another format within the industry. In 2013 e-books had become part of the “normal” book market.

In 2013, Nielsen’s Books & Consumers survey shows that among U.S. buyers of adult fiction and nonfiction, 25% of book buyers bought an e-book; 31% of new books purchased in adult fiction and nonfiction were e-books; and 15% of the dollars spent on these books were for e-books.

Adult fiction is the category most affected by the move to digital, and the format accounted for about 40% of e-book purchases in 2013. The increase in e-books’ share of book spending showed smaller growth than in unit terms, mainly because of the increase in self-publishing. It’s now estimated that around 10% of fiction e-books bought are self-published—and they are most commonly bought for under $3, whereas mainstream fiction e-books average $4.77 per new unit sold. Overall, the average price paid for a fiction e-book dropped to around 57% of that paid for mass market paperback fiction and approximately 37% of that paid for trade paperback fiction in 2013.

Internet-only retailers continued to dominate the e-book market in the U.S. and represented more than 9 in 10 adult fiction purchases in digital formats; furthermore, 1 in 4 new print books in 2013 were purchased online. But there is little evidence that bookstores are no longer relevant. In 2013, while e-commerce book buyers reported that they “trust this site” and may stay loyal because they are a “member of (a) frequent shopper program,” sentiment toward “delivery terms,” “ease of purchase,” and “book selection offered” dropped year on year. The reverse can be said of chain bookstores: factors such as “ease of purchase” and “book selection offered” held strong in 2013, although “special offers” and “sales” were less influential. Similar reasons are cited for independent bookstores, though being “conveniently located” holds sway and increasingly “staff knowledge” is a vital aspect of why consumers prefer an indie store.

Much of the growth in the e-book market is, of course, driven by device ownership, with the numbers of owners increasing when new devices become available, especially after the holidays. Access to suitable devices rose among American book buyers in 2013, although mainly through increased ownership of tablets and smartphones rather than dedicated e-readers. By the end of last year, more than half of book buyers (60%) were in a household with a tablet device, and nearly three-quarters owned a smartphone. In January 2014, tablet ownership was more than double that of dedicated e-reading devices, having overtaken the latter in popularity in the fall of 2012.

In the U.S., around 1 in 4 of all book-buyers purchased at least one e-book each month. Although this proportion did not grow significantly in 2013 after an uptick in the first quarter, initial data on the 2014 market seems to indicate that Christmas gifts of devices has resulted in a similar uptick this year, too.

Despite the increase in tablet ownership, at least 40% of e-books in the U.S. were bought to read on a dedicated e-reader device, rather than a multifunction device in 2013. More than one third (35%) of the books bought by tablet owners were digital in 2013: 56% of their book purchases were printed books. While we noted earlier that the overall book market has grown, albeit slightly, on a unit basis, one notable trend was the decline of people buying booksof any sort, print or e-? sjr as gifts. The gift percentage has been declining fairly steadily since 2009 when we first started tracking this information, and declined from tk% then to tk% in 2013.

As book buyers become more engaged with new devices and digital reading, there is less certainty about the appeal of books. Are device hungry kids still into books? Are consumers as confident about buying physical books for someone who usually reads on a device these days? And if not, would they want to give something that can’t be wrapped up to put under the Christmas tree, even if they know how to give them an e-book in the first place? Is it harder to know what people have already read when the evidence of their reading is on a device, not a bookshelf? This drop in gift books is one of the most important trends for the industry to consider as we monitor book purchasing in 2014.

The 2013 Books & Consumers Annual Report will be available shortly; for further details, contact mo.siewcharran@nielsen.com.