Amazon's marketing data vault is now open to every seller, and 97 percent have not noticed

For five years, Amazon Marketing Cloud was effectively locked away, available only to billion-dollar brands, while ordinary sellers guessed at who their customers were. Amazon has now quietly opened the data vault to all sellers, and an estimated 97 percent of them either do not know it exists or do not know how to use it.

The platform reveals exactly who is buying, when they buy and what prompts them to add a product to their cart. It maps the precise buyer journey that leads to a purchase, shows which audiences actually convert rather than merely click, and lets advertisers build custom audiences with a demonstrated propensity to buy more.

The more advanced play pairs the Marketing Cloud data with Cosmo, Amazon's AI engine, to surface buyer patterns that competitors cannot see, effectively putting the marketplace's own algorithm to work for the seller rather than against them.

Training sessions held in late October walked sellers through using the data to analyze ad performance and shopper behavior ahead of the fourth quarter. The window of advantage is expected to be short: once the broader seller base discovers the tool, the first-mover edge weakens.