Dive Brief:

• As more millennial shoppers buy the majority of their apparel and accessories online, apparel retailers must embrace an “always on” mentality, emphasizing integration of in-store and online customer experiences and de-emphasizing seasonality, according to new research from performance marketing technology company Criteo.

• The report, detailing apparel shopper behavior and technology, also found that about one third of all apparel purchases were made via mobile phones during weekends in December 2016 at the height of the holiday shopping season.

• Sundays were also found to be peak online cart-filling days during the November-December stretch, with the average online cart size hitting a high of $126 on Sunday, Nov. 13, with Sunday, Dec. 7 as the second biggest day during those two months.

Dive Insight:

If Sunday is a peak online shopping day, that potentially suggests shoppers might be finding items in-store and through other channels during the week, but waiting until the end of the week when they had more time on a day off from work to make a purchase. This is a shift in apparel-buying behavior that retailers and apparel brands will need to deal with, and as with many other market shifts, those darn millenials are behind this one

"The apparel and accessories category is witnessing a massive transformation," Jonathan Opdyke, president of Brand Solutions at Criteo, said in a statement announcing the report. "Millennial shoppers purchase the majority of their clothing and accessories online and retail storefronts are shifting to showrooming, in which shoppers can experience in real life and then purchase online. Apparel brands and retailers must embrace the new 'always-on' retail paradigm, where seasonality plays less of a role and in-store and online technology innovation enhances the shopper experience."

Being freed from the confines of seasonality would be a positive notion in many industries, but in apparel retail it guides everything from inventory management to advertising spending. Combined with the rise of e-commerce, it's a difficult change for apparel retailers to deal with, and right now many are responding by shuttering brick-and-mortar stores. That's what rue21 just announced it is doing, what The Limited in January said it was forced to do and what Ralph Lauren did this time last year.

Criteo has some familiar-sounding advice for these apparel retailers: Embrace technology like augmented reality to enhance shopping experiences; leverage sponsored product listings to drive awareness and sales; add content and lifestyle elements to e-commerce sites; and increase personalization.

But right now apparel retailers still seem to be getting backed up on defense to do much on offense. If they keep closing stores, they will have no more stores left to become showrooms. They need to have a broad, long-term vision that includes all of their platforms and above all a commitment to customer-centric initiatives — reflective of what customers want out of their stores. Among many other things, that means not telling customers what's available for them to buy based on which season it is, and which one is coming.