It’s on.

There’s a new twist in the battle between Amazon and Wal-Mart.

Today, in a blog post, Wal-Mart announced a rival sale to match Amazon's Prime Day.

In a direct hit to Prime Day — Amazon's one-day shopping event on Wednesday, July 15 that is open only to Amazon Prime customers — Fernando Madeira, Wal-Mart President and CEO, writes that Walmart.com is offering awesome deals of their own this week that will be available to everyone with "no admission fees" or "hidden costs."

Here’s the quote where they take a jab at Amazon: “We’ve heard some retailers are charging $100 to get access to a sale. But the idea of asking customers to pay extra in order to save money just doesn’t add up for us.”

The Wal-Mart deals will no doubt include rollbacks (Wal-Mart speak for deals) on thousands of items and product categories similar to those being offered by Amazon. And according to Wal-Mart the deals will extend beyond a single day. The rollbacks will begin this week along with some “atomic deals” that will be released in a few days. Finally, Wal-Mart is also dropping the free shipping minimum order to $35 from $50 to compete with Amazon’s free shipping for Prime Members.

So much of this is retailer hokey-pokey. Amazon clearly wants to beef up Prime memberships (they are offering a 30-day free trial offer during Prime Day to those who don't have a Prime membership.) And Wal-Mart recently began testing Shipping Pass, a members only shopping program that costs $50 a year – half the cost of Amazon's $99 Prime program — which gives members free three-day shipping on Walmart.com orders.

Not to be left behind, Target.com is offering a bunch of discounts through July 18 . The "Black Friday in July" sale currently features BOGO 50 percent off and extra discounts on items like clothing, shoes and fragrance.  Target's minimum purchase for free shipping is $25.

But what does it all mean for shoppers looking for the best prices? That remains to be seen.

Philip Dengler of BestBlackFriday.com has issued a challenge to Amazon, asking them to beat their prices from Black Friday 2014. Here's a breakdown of Amazon's Black Friday prices for TV's according to Dengler's data (check the website for historical pricing on games and other electronic items):

  • 32-inch LED TV for $79 – lowest price for a 32-inch TV
  • 40-inch 1080p LED HDTV for $119 – Price matched by Target and Costco for a 40-inch TV
  • 50-inch 1080p LED HDTV for $199 – Price matched by Best Buy and Fry's Electronics for a 50-inch TV
  • 55-inch 1080p LED HDTV for $395 – This price came from Target and no other stores were able to match it
  • 65-inch 120 Hz LED TV for $648 – Price matched by Walmart for a 65-inch TV

Will Amazon go lower than these prices on Prime Day? Dengler thinks not. Which means Prime Day may not be “better” than Black Friday, but it could be similar. And with Wal-Mart jumping in the fray, there is some incentive for both retailers to at least match pricing on identical items.

Of course the only way to know if you're getting the best price from Wal-mart or Amazon's Prime Day or any other retailer sale this week, will be to take Amazon up on their 30-day free trial offer so you can participate in Prime Day. Just remember to turn it off after 30-days or it will automatically upgrade to a paid membership.