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You will see “Amazon changes prices 2.5 million times a day” on many sites. This page traces where that figure comes from, adds the other documented facts, and says plainly what nobody outside Amazon knows.
Dynamic pricing means a seller changes prices often based on demand, stock and competitors. The best-known figure, more than 2.5 million Amazon price changes a day, comes from a December 2013 Profitero release that did not publish its method. Amazon has not confirmed how its pricing works today.
Correction. An earlier version of this page described price-tracking tests that Zroppix did not run. We removed those numbers. Everything below comes from the sources linked, which we read on the dates shown, or is labelled as our own advice.
The 2.5 million figure
Profitero’s December 2013 release said Amazon.com made more than 2.5 million price changes a day, up tenfold in twelve months from 269,113 at the start of December 2012. The same release gave 52,956 price changes for Best Buy and 54,633 for Walmart during all of November. Those time bases differ, so the comparison is not like for like, and the release does not explain how the data was collected or what counted as a price change. It is a thirteen-year-old number from a price-monitoring vendor. Treat it as a sign that large retailers reprice often, not as a current measurement.
What the FTC has alleged
In court filings reported in 2023, the FTC alleged that Amazon used an algorithm, Project Nessie, to predict where it could raise prices and keep them there when other sites followed, and that it earned more than $1 billion in excess profit (per NBC News). Amazon says the system was old, ran on a subset of products and was scrapped. This is an allegation, not a ruling.
Personalised pricing
The FTC’s January 17, 2025 release summarised staff analysis of documents from six companies (Mastercard, Accenture, PROS, Bloomreach, Revionics and McKinsey). It said retailers and intermediaries can use data such as location, browsing patterns and shopping history. It gave only hypothetical examples and did not report observed price differences, and the study was still ongoing.
A separate test is real but is not about Amazon: a study by Consumer Reports, Groundwork Collaborative and More Perfect Union found Instacart showed the same grocery item at different prices to different shoppers, by up to 23% (Groundwork Collaborative). Instacart said on December 22, 2025 that it would end the experiments.
What nobody outside Amazon can tell you
- How many price changes Amazon makes a day now.
- Whether Amazon charges different shoppers different prices for the same item from the same seller.
- How any one product’s price will move next week.
What this means when you shop
Prices on any large site can move, so a single look is a snapshot. Compare the seller, shipping and the exact model, and look for a dated earlier price before you decide. The lowest-price method and the FTC study explainer go further.
Sources: Profitero (Dec 9, 2013); NBC News on the FTC’s Amazon filings; FTC (Jan 17, 2025); Groundwork Collaborative on Instacart. All read November 1, 2026.
How this post was made. Rewritten on November 1, 2026 by the Zroppix team with AI assistance (Claude, from Anthropic) to remove tests we had not run. The facts come from the pages linked here, and we say where a source is secondhand. This page has no affiliate links. We make Zroppix and sell Zroppix Pro, a paid plan.