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If you are heading to the store on Saturday, you might be paying top dollar for your groceries.
A new study from data research platform Decodo reveals that grocery prices hit their peak on Saturdays at major retailers, while Mondays and Wednesdays offer the biggest bargains. Analyzing 1.5 million items across 120 e-commerce platforms, researchers found that price cuts are heavily concentrated on specific weekdays both online and on digital shelf labels (DSLs).
DSLs allow grocers and retailers to instantly update cost labels at the touch of a button, normalizing dynamic pricing and changing them daily, depending on command.
Walmart and Kroger’s use of DSLs have sparked controversial debate for shoppers who are concerned about grocers using data to track what customers are buying and when — with the intent to jack prices.
Walmart first introduced DSLs in 2023 and denied that the tags are used to rapidly raise product prices. The retailer promoted DSLs for their paper waste reduction and ability to give staff more time to spend with shoppers, instead of replacing price tags. The Walmart mobile app can also now trigger a flashing LED light on DSLs to help customers locate a product they see on the app. The price tag will flash in-store for the product the customer clicks in the app.
Walmart told The Post in June that its DSL system does not allow prices to increase during store hours as items are locked in for the day. If shoppers spot a change during the day, it would only be a price decrease.
Kroger has been using the digital shelves since 2018 but was investigated for surge pricing last year by Senator Elizabeth Warren and former Senator Bob Casey. The senators wrote to Kroger’s CEO Rodney McMullen, requesting information on how the chain uses the technology and its justification.
Grace Vitke with Decodo said to shop on Mondays when going for groceries because that’s when price decreases are “most concentrated” and when stores “try to keep the in-store prices aligned with online prices and promotions.”
Decodo also revealed that it’s unlikely prices will change between when shoppers pick up an item in the store and when they check out.
Despite growing concerns about price changes, DSLs are here to stay. By the end of 2026, Walmart plans to equip all 2,300 stores with DSL technology, saying it significantly reduces the time it takes to update price tags from 48 hours to mere minutes.
Retailers like Whole Foods and Kohl’s are following suit, believing it will lead to more consistent pricing, improved customer service and saved labor costs.
