Lululemon Athletica, seen here, sells plenty of leggings. But Amazon is selling more of these garments online than any other retailer. (Xaume Olleros/Bloomberg)

It’s been clear for some time now that Amazon.com has ambitions of competing more seriously in the fashion business: The e-commerce site has been investing in private-label clothing brands. It launched a nightly, QVC-like streaming show to tout its apparel. And it has lured big-name brands such as Kate Spade to sell goods on its site.

It appears those efforts are paying off. New data from Slice Intelligence, an e-commerce analytics firm, underscores just how much of a threat Amazon now poses to traditional clothing retailers. (Jeffrey P. Bezos, chief executive of Amazon, owns The Washington Post.)

Over a one-year period, Slice examined shoppers’ online purchases of two wardrobe staples: Denim and leggings. The analysis included about 236,000 shoppers, and the findings show that Amazon has hustled its way to some big market share.

[Why are sales suffering at so many women’s stores? They made ugly clothes.]

For leggings, Amazon had the largest market share of any retailer, drawing 11.6 percent of purchases. Nordstrom was close behind with 10.8 percent market share. But other chains should be shaken by what they see here: Amazon’s market share is more than triple that of Macy’s, and it’s more than double that of the Gap.

When it came to denim, Amazon also gobbled up greater share than many brands that have been in the jeans game for much longer. Amazon had the third-largest market share in denim, capturing 9.3 percent of purchases, putting it behind only Old Navy and Nordstrom. The e-commerce site came in just ahead of Gap, which had 8.6 percent share of denim orders, and it was far ahead of Macy’s, Kohl’s and Levi’s.

For both garments, Slice told The Washington Post that Amazon had increased its market share from the previous one-year period. The chart below shows the full results for the most recent year:


Screengrab courtesy of Slice Intelligence.

Indeed, this data only reflects how people are buying two specific garments. But leggings and jeans are particularly important garments: Industry insiders have been known to say that “bottoms” are key to building loyalty to a clothing chain. When a woman finds that pants from a certain store fit her, she’s hooked, and she’ll hit that store up for jackets, blouses, shoes and so on.

In this way, Amazon’s strength in these wardrobe staples might be an early indicator that the e-commerce giant has momentum in other apparel categories.

The Slice findings dovetail with other analyses that have found Amazon is turning up the heat in the clothing business. Investment firm Cowen & Co. back in 2015 forecast Amazon would easily surpass Macy’s in 2017 as the largest seller of clothing in the United States.

This leaves clothing and accessories brands with some difficult choices to make: They can start selling their wares on Amazon, acknowledging they might as well go where their shoppers are already on the hunt. Especially at a moment when department stores are struggling, this might be an important avenue for reaching new customers.

And yet, Amazon’s site doesn’t exactly have a sheen of exclusivity or glamour to it. It’s the so-called “everything store,” the place where you buy paper towels and baby formula. For example, the chief financial officer of Louis Vuitton’s parent company recently told investors, “We believe that the existing business of Amazon doesn’t fit with luxury, full stop. ”

Even for brands that aren’t as wallet-busting as Louis Vuitton, that’s a trade off they’ll have to consider: Will shoppers really perceive a brand as aspirational if they see its cocktail dresses next to cat food?

The online retailer plans to hire 120,000 temporary workers in the U.S. this holiday season, 20 percent more than last year. It's a sharp contrast to the cautious plans of traditional retailers. (Reuters)

[Just how much more money can retailers stretch out of yoga pants?]

The Slice Intelligence report also examined how online orders of leggings — a cornerstone of the red-hot “athleisure” look — were generally stacking up against orders of jeans. Online purchases of leggings were up 41 percent over the last year, compared to a 3 percent increase in orders of jeans. This difference is not terribly surprising, since jeans have been a staple of women’s wardrobes for decades.

More interesting, though, was that Slice found that, leggings are not just on a growth tear: The volume of orders for these items actually surpassed orders of denim in each of the last three months. While there is a big push in the apparel industry this season to introduce fresh denim looks such as wide-leg styles and asymmetric hems, these findings might suggest these new aesthetics may not quite have captured women’s imaginations yet.

Jaimee Minney, Slice’s vice president of marketing, said this pattern might also reflect the fact that leggings are more of a “utility” item: Some women might be wearing them for workouts or as pajamas, while others might be wearing them to the office. Leggings, these days, have more use cases than jeans.

I might say that the death of denim has been greatly exaggerated,” Minney said. But, she added, “This american classic apparel item is beginning to be surpassed by leggings.”