Amazon is celebrating its 20th anniversary this week, and to ensure it's going to be a good one, the retail giant is promising "more deals than Black Friday." On Wednesday, July 15, it will offer Prime subscribers limited-time reductions on thousands of products across various categories.

The offers will be available as Lightning Deals, which will be popping up as often as every ten minutes, as well as through seven Deals of the Day promotions. Free shipping will also be available on all of the products included, Amazon says — but there is a catch.

"Prime Day" reductions will only be available to Prime subscribers — new and existing — who live in the U.S., the U.K., Spain, Japan, Italy, Germany, France, Canada, and Austria.

"Prime Day is a one-day only event filled with more deals than Black Friday, exclusively for Prime members around the globe," said Greg Greeley, Vice President of Amazon Prime. "Members tell us every day how much they love Prime and we will keep making it better."

Amazon is promising reductions on thousands of products across dozens of categories, including electronics, toys, movies, clothing, patio, lawn and garden, sports and outdoor items, and more.

If you aren't already a Prime customer, you can sign up now and you'll be eligible for all of the reductions on Wednesday. And if you haven't had Prime before, you can take advantage of Amazon's free 30-day trial to get you started.