In this Tuesday, May 9, 2017, photo, a package from Amazon Prime is loaded for delivery on a UPS truck, in New York. Amazon is extending its annual "Prime Day" promotion to 30 hours this year. Amazon will offer discounts and other deals in an effort to boost sales during the slower summer months. This year's Prime Day will start at 9 p.m. ET on July 10, 2017. While Amazon has claimed success, there have been grumblings that Prime Day deals have been unimpressive or involve older models. (AP Photo/Mark Lennihan)

Amazon is extending its annual "Prime Day" promotion to 30 hours this year.

Amazon will offer and other deals in an effort to boost sales during the slower summer months. The deals are open only to members of Amazon's $99-a-year Prime loyalty program, so Amazon typically gets more sign-ups, too.

While Amazon has claimed success, there have been grumblings that Prime Day deals are unimpressive or involve older models. Last year, Benchmark analyst Daniel Kurnos called Prime Day an example of "how to make clearance look good."

This year's promotion will start at 9 p.m. ET on July 10 and end at 3 a.m. ET July 12. It used to run for 24 hours. It will be available in 13 countries, including the U.S., U.K., Germany, Japan and China.

© 2017 The Associated Press. All rights reserved.