Shoppers Have a New Way to Save Money at Walmart

— -- Retail behemoth Walmart has introduced an online tool likely to delight customers and frighten competitors: the Savings Catcher comparison tool. The tool allows Walmart shoppers to see if they could have gotten their purchases for less at another store and then refunds them the difference, if so.

Here's how it works. After shopping at a Walmart store, customers can visit Walmart.com or use Walmart's mobile app. Simply type in your receipt number (you can find it near the bottom of each Walmart receipt) and the date you shopped. The Savings Catcher tool then compares your purchases with prices for those same products as advertised in other retail store circulars. If the tool identifies an advertised price that is less than what you paid at Walmart, you get a Walmart eGift certificate for the difference.

On the pro side, Walmart has offered price matching for years and this tool automates the process. Previously, customers had to check competitors' ads themselves and request a price match at the Walmart checkout, so this is far easier. If I'm going to be picky and offer a "con," it's that the price reduction doesn't just happen automatically at the register. Perhaps that day will come, but, for now, customers must take an extra step. Walmart's tutorial also says the "Savings Catcher" only looks at "eligible" items, so presumably, some types of products are excluded, which might mean savings missed.

Still, anything that makes price matching easier for customers is welcome because it's one of the essential tools for any "guerrilla grocery shopper" who wants to save big money. When I did a price matching experiment of my own, I found this technique could bring grocery bills down by as much as 40 percent, bested only by creative couponing and stockpiling as strategies.

A similar service, Citi Price Rewind, refunds the price difference on Citi credit card purchases you've made within 60 days, with the exception of tickets, and certain large ticket items like jewelry and boats.

Walmart says Savings Catcher will initially index roughly 80,000 products and will later add fresh produce and more. So check it out and--if you like the savings you see--ping the company and let them know so they'll expand the tool further, faster.

Opinions expressed in this column are solely those of the author.

Elisabeth Leamy is a 20-year consumer advocate for programs including "Good Morning America" and "The Dr. Oz Show." She is the author of “Save BIG” and “The Savvy Consumer.” Elisabeth is also a professional speaker, delivering talks nationwide on saving money, media relations and career success. Elisabeth receives her best story tips from readers, so please connect with her via Facebook, Twitter or her website to share your ideas.