Of the 88 years that New York City’s iconic independent bookseller Strand Bookstore has been open, 2015 was its highest year ever for revenue. The bookstore’s aisles have been crowded over the past 12 months and they are packed to capacity this week, the peak of the holiday season.

“We haven't been able to keep some of the books in stock,” Whitney Hu, marketing director at Strand, told International Business Times. “It's been a crazy year. Our employees on the floor have been in overdrive.”

With CD and DVD sales in a state of secular decline, printed books are emerging as one of the last remaining physical media. This is especially noticeable around the holidays, as procrastinators around the country scramble for last-minute gifts. But while the holiday season normally gives bookstores a significant sales boost, retail sales data for printed books shows that the story for the book industry as a whole is a bit more complicated.

Sales of printed books are down slightly over the past year, continuing a trend of steady decline seen over the past five years, multiple data sets show. Sales of e-books remain unchanged, or continue to rise, depending on whom you ask.  

Total publishers’ book sales, which include both print and digital e-books, remain mostly unchanged, according to data from the  Association of American Publishers (AAP), which analyzes book sales data from 1,200 publishers in the United States. Americans read slightly fewer books in 2015 than they did in 2014, according to a Pew Research Study of about 1,000 people. The number of people who read printed books is down about 5 percent, while consumption of e-books remained unchanged.

Does that mean it’s s all doom and gloom for printed books? Not exactly.

"It's a mixed bag for print in 2015," said AAP spokeswoman Marisa Bluestone. Indeed, sales of paperback books grew 12 percent from January to August, compared to the same time period last year, according to AAP data. Meanwhile, the American Booksellers Association saw an increase in the number of member store locations, according to the organization’s media director. There were 2,227 locations in 2015, up from 1,660 locations five years ago.

On a heavier note, sales of hardback books shrunk about 8 percent this year from last year over the same eight-month period, and the print market as a whole is declining.

e-reader E-reader sales will continue to grow, globally and in the U.S. Pictured: A girl looks at a Sony e-book at the 2012 Frankfurt Book Fair. Photo: Hannelore Foerster/Getty Images

Global Crunch

Internationally, the combined market of print and audio books will fall 3 percent each year for the next four years, according to data from PricewaterhouseCoopers. Some regions, like Latin America, the Middle East and North Africa, are still expanding their book markets, offsetting steeper declines in other countries like the United States.

Revenue in the U.S. will decline at an average rate of 8 percent. While avid literacy advocate Benjamin Franklin would no doubt be disappointed in such a trend, American publishers needn't sound the death knell yet. “There will be a long happy life for print books,” said Chris Lederer, principal at strategy consulting firm PwC’s Strategy&.

And while e-books complicate the industry narrative, they also help paint a slightly brighter story. Revenue from e-book sales will grow about 10 percent each year over the next four years in the U.S. and about 15 percent worldwide, according to PwC. The slightly slower growth in U.S. e-book revenue is because the country already experienced its e-book boom during 2009-2011, experts say. Amazon’s first Kindle e-reader, released in 2007, had a profound effect on the book market, but sales of e-readers have cooled off in recent years.

Some say that the e-book boom is even greater if you consider the number of self-published books sold through Amazon. While the online behemoth does not release its e-book sale data, according to multiple experts, one e-book industry blog "Author Earnings" web-scrapes information to get a snapshot. According to the blog, self-published books, or indie books, are making up an increasing number of e-books sold through Amazon, which consistently reports strong sales. In fact, Neal Thompson, Amazon’s director for author and publishing relations, said that more than one third of Amazon's U.S. top 100 e-book best sellers are self-published books, according to an interview with LiveMint.

The takeaway is the same for both print loyalists and e-book enthusiasts alike: You’re still more likely to see someone reading a print book rather than an e-book in the park or on the subway for at least for the next few years. But e-book lovers will have more and more company as the digital market share increases.