Rock, paper, scissors. Amazon always seems to win.

Is there any sector that the Internet juggernaut isn't taking down?

Its latest target is office supplies. Essentially, if you sell paper products, or anything that uses paper - say, notebooks or books - you're facing challenging times.

No wonder that Staples, Office Depot, and Barnes & Noble are all "streamlining" operations and closing hundreds of stores.

As it awaits a federal judge's ruling on its proposed merger with Office Depot, Staples just announced it was downsizing nationwide, with store closures, reduced hours, and layoffs.

Adam Riddle, 29, of Levittown, shopped at a Staples in Langhorne last week to buy a planning notebook for $16.99. He said the reason for the store closings was obvious:

"You can pretty much email everything now," said Riddle, a communications signal manager at Amtrak. "I only come here if I can't get something at work."

He's right. All the office-supply players used to dabble in various media sales, ranging from CD-ROMs to software. Most of that has gone away or online.

"Online dominance is the new norm for office supply sales," said analyst Garrick Brown, head of retail research for Cushman & Wakefield. "The good news for Staples is that they are the dominant player still, thanks to its early embrace of e-commerce.

"Amazon certainly has made headway, as they have in every retail category," he said. "Walmart also has picked up some online market share here. But the dominant player for office supplies is still Staples."

But for how long?

The company's moves to close brick-and-mortar stores and shrink others are to better compete in a new retail reality starring Amazon, experts say.

Apparel retailers, such as the Gap and Macy's, are deploying the same strategy "to become more nimble," as they like to say, with a smaller store fleet.

Brown said Staples' model, taking a 25,000-square-foot store and expanding it to 40,000 square feet, is now outdated. Such demand no longer exists with the shift to online shopping, and with schoolchildren using more laptops and iPads vs. traditional notebooks and paper.

Staples is doing all it can to survive while trying to buy out Office Depot.

But the merger has met stiff resistance from the Federal Trade Commission on grounds that the new company would be too big and would lessen competitive pricing.

A hearing is set in federal court next month to see whether Staples can come up with a plan that the FTC will approve.

Anthony Chukumba, a senior research analyst at BB&T Capital Markets, said Staples is faced with "the perfect storm of reduced demand and increased competition."

Staples generated approximately $21 billion in sales last year and currently has about 2,000 stores. Office Depot generated approximately $14 billion in sales and has just under 1,600 stores in North America.

"You just don't need as much ink, toner, and paper as you once did in a digital world," Chukumba said. "And who buys fax machines or CD-ROM discs anymore?"

"There's no question there's more competition from online retailers, like the Amazons of the world. Our research shows Amazon routinely undercuts Office Depot and Staples' prices by over 20 percent, on average," he said.

"It shows what a robust competitor Amazon is. Amazon has been able to leapfrog Staples and Office Depot in terms of user experience, even though the office supply retailers had a huge head start from their legacy catalog businesses."

Staples has begun to diversify its revenue stream the last few years, including expanding into janitorial and break room supply sales. This has allowed companies that are already Staples customers to order office cleaning and other products to get better deals and all-in-one delivery.

Staples now generates more than $1 billion of sales annually in this product category, according to Chukumba, and it's one way to hedge its bets against the growing threat of Amazon.

Moody's lead retail analyst Charlie O'Shea gave a glowing fourth-quarter 2015 review of Amazon. The online giant grew product retail sales by $3.5 billion, or 15 percent year-over-year, and expanded margins.

He contrasted Amazon's performance to the possible Staples/Office Depot merger: "While we continue to believe in the merits of the transaction, especially as competition heats up in the office supply segment led by Amazon, the companies are fighting a tough uphill battle with the FTC," O'Shea said.

And that's why the paring continues at Staples, which offers same-day online delivery if orders are placed before 3 p.m. and has an online pickup counter at every store.

"Staples has too many stores, and closing some is not a bad thing when you have this transformation going on online," O'Shea said. "There's no question that paper has seen better days."