How Retailers Are Using Dynamic Pricing to Track Shopper Behavior—and What It Means for Your Wallet
Consumers trying to score the best deals online may be facing a moving target as retailers increasingly lean on dynamic pricing—a strategy that adjusts prices in real time based on demand, inventory, and individual consumer behavior. A new investigation by CBS California reveals just how volatile those prices can be, leaving shoppers guessing when to buy.
CBS California Investigates tracked randomly selected shopping carts at three major retailers—Old Navy, Target, and Amazon—over several weeks. The findings: prices fluctuated significantly, often making it nearly impossible to determine the best time to make a purchase. At Old Navy, the total cost of items in one cart swung from a high of $225 to a low of $143 between April 29 and May 26—a difference of roughly 36%. Prices changed almost daily; for instance, the cart total dropped from $201.46 to $184.96 in a single day.
“Dynamic pricing allows retailers to adjust prices in real time using data about supply, demand, and consumer purchasing habits,” said Anthony Dukes, a marketing professor at the USC Marshall School of Business. He explained that these algorithms factor in shopping habits, demographics, and other characteristics because retailers know consumers have different price sensitivities and willingness to pay.
Some shoppers may see higher prices simply because they’ve paid more in the past, while price-conscious buyers might be offered lower rates. Retailers can also consider gender, time of day, day of the week, and even the type of device a consumer is using, Dukes noted.
These practices have accelerated in recent years thanks to advances in data analytics and machine learning, leading to what experts call a “personalized pricing” environment. The goal is to extract maximum revenue from each customer—but the result for consumers can be confusion and frustration.
Kat Wilson, an online shopper, says she used to “price shop” by waiting for sales, but that strategy no longer works. “Even if I put it in one day and then a couple of days later, I check it and then the price has gone up, so then I wait until it goes back down,” she said. “It’s become a guessing game.”
Target’s monitored cart—containing six clothing and shoe items—fluctuated between $170.11 and $135.54 over two weeks, a difference of more than 20%. Amazon’s cart, with seven food, clothing, and shoe items, showed smaller swings, rising from $269.08 to $274.57 in the same period.
Dukes suggested that some retailers intentionally randomize prices to prevent shoppers from predicting when a better price will appear. “If it were predictable, then customers would know when the better price is coming and just simply wait for it,” he said.
The practice differs sharply from brick-and-mortar stores, where price changes are tied to logistical constraints like manual tag replacements and infrequent sale cycles. Online retailers continuously update prices—sometimes several times a day—using algorithms that analyze competitor data and demand in real time, according to research by Competition Policy International.
CBS reached out to all three companies. Old Navy did not respond to three email inquiries. Amazon said in a statement that it keeps prices low and changes them to match competitors, offer deals, or reflect updates by independent sellers—emphasizing it does not adjust prices based on a consumer’s shopping habits or behavior. The company cited third-party analytics from Profitero, which ranked Amazon as the lowest-priced U.S. retailer every year since 2017, with online prices averaging 14% less than major rivals in 2025.
Target acknowledged that several promotions occurred during the monitoring period, including a 30% discount on dresses and a $10-off-$50 promotion, which could explain the fluctuations.
For shoppers like Wilson, the unpredictability is deeply frustrating. “When prices are so up and down, how do you know if you’re getting a good deal? You don’t. It’s a catch-22. You just have to wing it, basically, and just hope for the best,” she said.
Some consumers say they would prefer consistent pricing over fluctuating sales and discounts, particularly amid rising inflation. “How are we supposed to save money with all this inflation and everything, and these stores are just going up and down with all the internet and pricing?” one shopper lamented.
Experts note that while dynamic pricing can benefit retailers by maximizing revenue and clearing inventory, it raises fairness concerns—especially when algorithms exploit behavioral data to charge some customers more than others for the same product. Consumer advocates urge shoppers to compare prices across devices, clear browser cookies, and use price-tracking tools. They also recommend checking retailer adjustment policies: Target and Old Navy allow price adjustments within 14 days for both in-store and online purchases, while Amazon does not offer price adjustments after purchase.