What it means
A10 is a widespread but unofficial term in the seller community: Amazon itself still calls its search algorithm A9 and has never announced an 'A10 update'. Sellers use 'A10' to describe observed ranking shifts — e.g. that external traffic, organic sales strength, and customer behavior supposedly count more than pure advertising signals. These observations are plausible but not officially confirmed. The practical takeaway: optimize for what demonstrably works — listing relevance, purchases after search, and a convincing customer experience — rather than for alleged secret A10 factors.