The Amazon Prime Day sale is back to its summer date and is underway, and Target and Best Buy are running tandem deals.

The Prime Day event has become an annual sale, but the deals were pushed to October last year because of the pandemic, bleeding into holiday sales. Back to its usual spot in the summer — it began Monday and continues Tuesday — merchants are hoping the sales bump will be back again as well.

However, consumers might not get as good a deal as in years past on Amazon. Rising shipping costs and advertising rates, plus scarcer inventory because of shipping disruptions, have pushed up costs. A number of Amazon suppliers said they were holding back inventory to make sure they have enough during the Christmas season.

"There's growing deal fatigue on Amazon," Peter Darch, who manages inventory and supply chain at Perch, which owns a number of brands that are popular on Amazon, told Bloomberg News. "We're being a little more selective with deals."

For the first time, Target Deal Days, which began Sunday, added an extra day, making it a three-day sale. Food and beverages also were included in the sale for the first time.

"Our industry-leading, safe and easy fulfillment options deliver same-day joy — with no waiting or membership fee required," said Christina Hennington, Target's chief growth officer, in a statement.

Best Buy's sales started June 14 and end Tuesday.

Target and Best Buy also announced that, like last year, they will be closed Thanksgiving Day.

Amazon said the company will offer more deals this year than last but didn't mention the size of the discounts.

"We continue to innovate and grow Prime Day to ensure our Prime members and selling partners find incredible value," a company spokesman said in a statement.

Amazon started Prime Day in 2015 to attract new subscribers who now pay as much as $119 a year for shipping discounts, video streaming and other perks. The event helps Amazon lock in shoppers before the holidays and deepen its relationship with existing customers by offering them deals on Amazon gadgets such as the Fire TV stick and smart speakers that run on the Alexa voice platform.

Amazon brands again this year took center stage, with deals on surveillance doorbells from the company's Ring division and a voice-activated Echo device for cars that will go for $15.

Amazon, which has posted record profits this year, can afford to discount heavily. Many consumer-products companies, though, are thinking about raising prices, making it tough to participate in a sale like Prime Day, said Shanton Wilcox, a partner at PA Consulting, whose clients include packaged-goods outfits dealing with inventory shortages.

"Prime Day is going to be less exciting than it has been in the past," he told Bloomberg. "You don't want to scare away demand, but you have to manage profitability."

Bloomberg News contributed to this report.