Pew Internet reports that the percentage of American consumers reading e-books jumped four percentage points, to 21 percent -- driven by strong holiday sales of e-readers and media tablets -- in comparison with the organization's prior survey in mid-December.

According to Pew's latest surveys, 43 percent of U.S. respondents said they had read either an e-book or other digital content on an e-book reader, tablet, PC, or handset screen during the previous 12 months.

With respect to book consumption in any format, print books still dominate, but e-books now have a notable audience. Pew's new study shows that 28 percent of Americans age 18 and older own at least one specialized device for e-book reading -- either a tablet or an e-book reader.

"The number of adults reading e-books on any given day has jumped dramatically since 2010," noted Pew report authors Lee Rainie, Kathryn Zickuhr, Kristen Purcell, Mary Madden and Joanna Brenner.

The shift toward e-book reading on a typical day is being driven by those who are college educated, those living in higher-income households, and those ages 30-49.

A Matter of Timing

Still, Pew report author Rainie told us that age was not as significant a factor as one might expect at first blush when it comes to those who are buying and reading e-books vs. the respondents who are limiting their purchases to printed books.

"Age differences did show up a bit, though they weren't as dramatically stark as 'older readers like print, younger readers like e-books,' " Rainie said in an e-mail Thursday.

"Younger readers were somewhat more inclined to e-books and older readers were somewhat more inclined to printed books, but the breakdowns were not very large," Rainie said.

The most avid users of today's e-reading technologies are those who read more frequently and tend to buy rather than borrow books and other digital content. Furthermore, 88 percent of the respondents who said they read e-books during the past year also continue to read books in print form.

"As a rule, dual-platform readers preferred e-books when they wanted to get a book quickly, when they were traveling or commuting, and when they were looking for a wide selection," the Pew study's authors wrote.

"Print was strongly preferred over e-books when it came to reading to children and sharing books with others, the report's authors said.

A Content Consumption Driver

According to Pew's new study, U.S.-based digital device owners read content more often than consumers of books and other written materials available in a traditional print format.

"On any given day 56 percent of those who own e-book reading devices are reading a book, compared with 45 percent of the general book-reading public," the authors of Pew's new study reported.

"Some 63 percent of the e-book device owners who are reading on any given day are reading a printed book, 42 percent are reading an e-book; and 4 percent are listening to an audio book," the report's authors added.

What's more, 41 percent of tablet owners as well as 35 percent of e-reading device owners said the amount of content they typically read has continued to rise ever since the technology first became available to them.

"The longer people have owned an e-book reader or tablet, the more likely they are to say they are reading more," the report's authors said. "Forty-one percent of those who have owned either device for more than a year say they are reading more, versus 35 percent of those who have owned either device for less than six months."