Amazon's Prime Day kicks off Monday night

CHICAGO (WLS) -- Starting Monday night, it's Christmas in July for Amazon Prime subscribers.

The third annual "Prime Day" kicks off at 8 p.m. Central Time. Amazon said it will offer new deals every five minutes for 30 hours.

One Chicago retail expert compared Prime Day to Black Friday or Cyber Monday in July. But he said before you hit "add to cart," make sure you're really getting a deal.

To get the deals, you need to be an Amazon Prime member, which costs $99 a year. But there are ways to avoid paying the full fee.

"Two adults - or as Amazon calls it, a household - can share a single account, so that's about $50 each," said Mark Ellwood, author of "Bargain Fever."

You can also sign up for a free 30-day trial of service. But a Chicago retail expert thinks many people choosing that option will pay the price.

"Prime Day for Amazon is all about capturing as much market share as they can. I think they're going to be up to 83- to 85 million Prime members by the end of the day," said expert David Weiss.

And Weiss has advice for current Prime members, new members, and those trying it out for free.

"Definitely price compare. Make sure that you are getting the best deal by checking, not just in the belief that you are. Amazon has everyone believing that they win on best price. They aren't always doing that," he said.

Meanwhile, Amazon opened a new corporate office in the Loop at Monroe and Wells streets.

The new corporate offices will create 200 jobs for the city. The company is looking to hire nearly 2,000 people across Illinois for nine fulfillment centers.

"Amazon is a global company that recognizes Chicago has the talent and transportation that can help it continue to thrive for years to come," Mayor Emanuel said. "I want to thank Amazon for making this commitment to Chicago's innovation ecosystem and look forward to working together as they continue to grow right here in the city of Chicago."

During the event opening the office, Amazon made a donation of $10,000 to Code Platoon, a non-profit that helps veterans transition to a civilian workforce.

Amazon also has five plants in Illinois and plans to add more.