Amazon.com Inc.’s Prime Day shopping event has become the kickoff to the important back-to-school season as shoppers increasingly go online for deals, a RetailMeNot survey shows.

Data from RetailMeNot found that 84% of retailers now consider the period around Prime Day the most important time for online sales during the back-to-school season.

Prime Day will take place over 48 hours from July 15 to July 16 this year.

“With the back-to-school shopping season starting with Prime Day, all retailers have an opportunity to capture early sales by participating in Prime-related promotions,” said Michelle Skupin, RetailMeNot’s senior director of marketing and communications, in a statement.

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Other peak shopping days are the first weekend in August and Labor Day weekend.

Shoppers are expected to spend an average of $507 for back-to-school, up from $465 last year.

RetailMeNot data shows that more than two-thirds of those shopping on Amazon during Prime Day will also head to other retailers. Parents will visit an average of 11 retailers throughout the Prime Day event.

Target Corp. TGT, +0.36% , eBay Inc. EBAY, -0.77% and Walmart Inc. WMT, +0.19% are among the retailers that have announced deals scheduled to coincide with Prime Day. Ebay has gone so far as to offer additional discounts if the Amazon AMZN, +0.06% site crashes.

RetailMeNot data shows that 64% of parents will shop on Prime Day this year, “nearly all” customers who shopped last year’s Prime Day event hope the experience in improved in 2019.

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RetailMeNot conducted an online survey of more than 1,000 parents between April 22 and April 26.

Most back-to-school shopping still happens in brick-and-mortar locations, with data from marketing intelligence company MiQ showing that shoppers will make an average of 16 trips to stores for back-to-school items between July and September.

However an increasing amount is shifting to digital, with almost 10% of 2018 purchases, or $8 billion worth, happening digitally.

MiQ notes that back-to-school shopping is impacted by the various school start dates across the country with some regions starting well ahead of others.

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Target is getting a jump with a Wednesday press release focused on all of its back-to-school offerings, including a School List Assist function on the e-commerce site that lets parents search by a student’s school or grade to purchase the necessary supplies, and new gear in the private-label children’s brand Cat & Jack.

And last week, Amazon launched a college-focused storefront that will offer exclusive perks to Prime Student members.