Consider a small, unremarkable electric ice-cream maker, listed at $17.99 on both Amazon and Best Buy. Then, without any obvious reason, it vanished from Best Buy's shelves — and its price on Amazon quietly tripled to $59.99.

For most shoppers, it looked like an ordinary market fluctuation. According to internal company emails reviewed by The Guardian and court claims filed by California's attorney general, it was anything but. For at least a decade, Amazon has deployed a set of techniques designed to pressure suppliers into ensuring that their products are never sold more cheaply elsewhere, California authorities allege in an ongoing lawsuit. The mechanism, as described in internal records, worked in two directions.

In some cases, Amazon employees flagged lower prices on rival sites — Walmart, Newegg, Home Depot — as direct threats to Amazon's own profitability, and then quietly reduced or threatened to reduce those suppliers' sales visibility on the platform. In other cases, Amazon matched a competitor's lower price and then demanded that the supplier compensate it for the revenue it had lost by doing so. Facing that financial pressure, suppliers found a far simpler solution: they raised prices at rival retailers, or removed their products from those sites altogether. The California attorney general's office obtained a large volume of internal Amazon emails, presentations and meeting notes as part of its price-fixing lawsuit, which alleges that Amazon engaged in widespread arrangements to raise or control consumer prices.

The Guardian examined those records alongside hundreds of pages of deposition testimony and interviews with fifteen current or former Amazon supplier representatives, employees and law enforcers. Amazon has not accepted the allegations.