The number of U.S. adults who own a tablet device nearly doubled after the holiday season from 10 percent to 19 percent, according to the Pew Research Center.

Measured from mid-December to mid-January, the impressive increase in tablet ownership means that approximately 29 percent of American adults now own either an e-reader or tablet device - up from 18 percent in December.

While the increase in digital readers may make a few publishing companies nervous, at least two companies are celebrating the news. Both Amazon, which makes the Kindle Fire, and Barnes & Noble, which makes the Nook tablet, also saw a large increase in sales compared to the previous year.

According to Amazon, the company sold four times as many Kindle devices as it sold on Black Friday in 2010, in part due to the introduction of the Kindle Fire.

"We knew Kindle Fire and the new E Ink Kindles would be highly desirable gifts this holiday season," said Wendy Fritz, senior vice president of Computing, Tablets and e-Readers at Best Buy.

At Barnes & Noble the Nook tablet saw a 70 percent increase in holiday season sales from the previous year, according to the company. As a result, Barnes & Noble is currently looking to capitalize on the digital sales by possibly spinning off the Nook division.

"We see substantial value in what we've built with our Nook business in only two years, and we believe it's the right time to investigate our options to unlock that value," said William Lynch, Chief Executive Officer of Barnes & Noble.

While success of the tablet and e-reader devices may seem like the death knell for small bookstores, the American Booksellers Association actually reported an increase in profit for independent bookstores during the holiday season, including a 15.5 percent increase in sales during the Black Friday shopping period. It remains to be seen if these customers will continue shopping in the new year.