NEW YORK (AP) — Amazon's annual "Prime Day" promotion that starts Monday will focus on new products, bringing Whole Foods into the process and persuading subscribers that Prime membership is worth the coming price hike.

Shoppers, meanwhile, will have plenty of sales to choose from as other retailers offer promotions to try to take a share of the spending.

Amazon is highlighting its Echo assistants and its own brands, particularly in clothing, said Deborah Weinswig, CEO of Coresight Research.

While Amazon doesn't disclose sales figures for Prime Day, Weinswig estimates it will generate $3.4 billion in sales worldwide, up from an estimated $2.4 billion last year. Prime Day also lasts six hours longer than last year.

Expanding Prime Day has increased the pressure on other stores and chains like Macy's, Nordstrom, Best Buy, Walmart and Target to roll out their own promotions, said Charlie O'Shea, lead retail analyst at Moody's.

"Brick-and-mortar retailers know that they have little choice but to continue offering their own deep discounts, which is evident in the proliferation of 'Black Friday in July' deals that are being launched earlier each year, as well as various 'price match' offers," he said in a note Monday.

Amazon created Prime Day in 2015 to mark its 20th anniversary, and its success has inspired other e-commerce companies to invent shopping holidays. Online furniture seller Wayfair introduced Way Day in April, becoming its biggest revenue day ever.

Prime Day also usually helps boost the number of Prime memberships. Amazon disclosed for the first time this year that it had more than 100 million paid Prime members worldwide. It's hoping to keep Prime attractive for current and would-be subscribers after raising the U.S. annual membership fee by 20 percent to $119 and to $12.99 for the month-to-month option.

Here's a look at what's happening this year:

WHOLE FOODS IN THE MIX: The Seattle-based company is offering Prime members who spend $10 at Whole Foods from July 11-17 a $10 Amazon credit to use on Prime Day. And at its more than a dozen Amazon Books stores, discounts will expand beyond devices.

NEW PRODUCT LAUNCHES: Several companies have agreed to launch new products on Prime Day, Amazon says. Among them, a Fingerlings unicorn doll whose horn lights up and a Delta kitchen faucet that can be turned on through Amazon's Alexa voice assistant.

PRIVATE LABEL PUSH: Amazon has been building its own brands, and it'll be offering deals such as 25 percent off its Rivet furniture brand, which didn't exist a year ago. Other deals include 30 percent off its Mama Bear diapers and baby products.

BACK TO SCHOOL: The company is making a big push in school supplies for Prime Day. It says customers bought more pencils, pens, notebooks, glue sticks, lunchboxes and backpacks on Prime Day last year than any other day of the year.

MORE COUNTRIES: Amazon has been expanding its Prime membership around the world, and four new countries will be a part of Prime Day this year: Australia, Luxembourg, the Netherlands and Singapore.