Walk up the stairs in the Staples store on Manhattan’s 5th Avenue on a steamy day in mid-July and you’ll see a gleaming display of back-to-school merchandise, full of notebooks, pens, backpacks and everything Staples wants to sell to New York City's kids for their upcoming classes -- classes that don’t start for another two months.

Big retailers are already revving up their marketing machines to draw students, parents and teachers into their stores for back-to-school season. For an office supplies chain like Staples, this period is as important as the end-of-year holiday season is for most retailers.

The National Retail Federation, a trade group that represents the industry, has acknowledged that American stores are experiencing a back-to-school “creep.” Traditionally, retailers began their promotions in late July, sometimes moving into the middle or early parts of the month. This year, consumers saw back-to-school ads as early as late June.

Staples launched its back-to-school section on Wednesday. Demos Parneros, president of North American stores and online at the company, said shoppers’ habits show they’re willing to start buying.

“Some probably think it’s too early, but thousands and thousands come through and shop,” Parneros told The Huffington Post in an interview this week.

Shoppers usually take two or three trips to compile all the gear they need for the first day of school, and they expect to have two or three weeks to do it, he said. And in many parts of the country, especially in the south, schools will be back in session in the next few weeks.

Allison Corcoran, senior vice president of marketing for North American stores and online at Staples, described school re-openings across the country as a “patchwork quilt.” The first day of school varies based on the school district, and often even adjoining towns may have different start dates. To handle demand, Staples maintains its stock of back-to-school products throughout the season.

Corcoran also said that Staples must cater to the “early shoppers” -- moms and teachers who have been waiting for back-to-school deals and want to avoid the last-minute rush as their deadlines loom. The day prior to the first day of school, plus the first day itself, are the busiest for shoppers, she said.

As the season progresses, Staples is banking on flashy neon stationery for kids, along with headphones and Samsung Chromebooks for older students, to be big hits.

But Brian Sozzi, CEO and chief equities strategist at Belus Capital Advisors, thinks Staples is making a mistake in deciding to start the back-to-school season now.

He called retailers “an arrogant bunch,” for thinking that just because consumers have instant access to information on new products, they'll want to buy, even if they don’t need to use the product for weeks or months. By lengthening the shopping season, retailers are implicitly saying that none of their products are “must-haves,” he said.

“The fact is, we as people no longer want to invest cash in merchandise to be used at a later date,” he said. “The season should not start this early.”