Late last month, (NASDAQ:AMZN) released some preliminary details regarding its annual Prime Day event. The customer loyalty sale will begin at midnight PDT on Monday, July 15, and in a first, will last for two full days, up from 36 hours last year. 

Attempts by rivals to get in on the action began almost as soon as Amazon dropped the initial press release. Target (NYSE:TGT) said it will debut its first-ever "Deal Days" sale, which will run at the same time as the Prime Day event.

eBay (NASDAQ:EBAY) announced a sale of its own and trolled its larger rival's troubles from last year by announcing a "Crash Sale," promising to offer deals that were "too good to be true" if Amazon's website went down again.

Now, the competition is going even further.

A screenshot of eBay's site The Brand Outlet showing various name-brand products at deep discounts.

Image source: eBay.

Heavily discounted name brands

On Monday, eBay announced the launch of "The Brand Outlet," a dedicated site that would offer discounts of up to 70% off a host of well-known brands, including Bose, Samsung, adidas, Rolex, Tiffany & Co., and DeWalt. To celebrate the debut of its site, eBay said it is offering "Hot Deals for Hot Days," "thousands of amazing deals" with some of the lowest prices of the season. 

Jay Hanson, eBay's VP and COO, Americas, said, "The new destination offers shoppers who love the thrill of the hunt for discounts, big savings during the prime summer shopping season across dozens of categories from electronics, apparel, shoes, accessories, health, toys, home to appliances."

Target also pulled back the curtain on some of the bargains that will be available during its Deal Days sale, saying on Monday that shoppers would find "hundreds of thousands of items" on sale at The retailer will offer up to 40% off select furniture and indoor rugs, 30% off exclusive home brands, toys, sporting goods, and appliances, and great deals on a number of name-brand products, including Instant Pot, Kitchen Aid, Shark, Dyson, Hoover, and many more.

The retailer put its trademark bullseye on Amazon's back, continuing to stress that there was "no membership required" for its deals, a potshot at the annual subscription price of $119 paid by Prime members. 

Amazon isn't resting on its laurels

eBay and Target aren't the only one ramping up the deals.

Since its initial announcement, Amazon has released additional details about new and exclusive deals in star-studded collaborations with the likes of Kristen Bell, Mark Wahlberg, Kobe Bryant, and JoJo Siwa, among others.

On Sunday, Amazon also announced a number of exclusive deals for Prime members at its Whole Foods Market stores. In a press release, the company said it would offer "some of the deepest discounts of the year on summertime favorites" as part of its Prime Day sale. Prime members can get discounts on select popular products at Whole Foods Market, plus an additional 10% off hundreds of sale items. 

Whole Foods Market in Addison, Texas.

Image source: Whole Foods.

One of the biggest deals will be available until July 16: Prime members who spend $10 at Whole Foods in store or on Prime Now will receive a $10 credit to use on Amazon for Prime Day. The company is also offering a list of select seasonal items and additional deals that will be announced each day. 

"Our vision is that Prime Day should be the absolute best time to be a member -- when you can enjoy shopping, savings, entertainment and some of the best deals Prime members have ever seen," said Jeff Wilke, Amazon CEO Worldwide Consumer, in a statement. 

Investor takeaway

We have yet to see who will come out on top in the head-to-head retail matchups involving Prime Day, but consider this: In the stock price showdown, eBay and Target are both besting Amazon so far this year, up 41% and 34% year to date, compared to just 30% for Amazon. If you choose any period two years and longer, it's all Amazon.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.