Amazon's Prime Day, which offers sales for members of the company's subscription program, will stretch from noon July 16 to the end of the day July 17.

Share story

Amazon is once again expanding its mid-summer sales day for members of its $119-a-year Prime program.

The fourth annual Prime Day, or in this case Prime Day-and-a-Half, will now extend for 36 hours, beginning at noon July 16.

Only Prime members can participate, but people can sign up for membership anytime before or during the sale or opt for a 30-day free trial.

The sales day began in 2015, starting as a typical 24-hour day, then expanding to 30 hours last year. Analysts estimated it brought in $1 billion for the Seattle e-commerce company in 2017.

Perhaps more important than that, Amazon announced last July that the 2017 Prime Day was the single biggest day for Prime sign-ups up to that point. The program now has more than 100 million members, Amazon disclosed for the first time in April.

Amazon’s Prime membership program offers two-day free shipping, access to some TV shows on its streaming service, discounts at Amazon-owned Whole Foods and a host of other perks. Its members also spend more on the site than non-members.

Prime Day 2018 will offer more than 1 million deals, and also include in-person discounts at Whole Foods, Amazon said.