Review Velocity

Amazon's A10 algorithm weights review velocity rather than review count. A listing with 50 new verified reviews in the last 30 days outranks (in this dimension) a listing with 5,000 reviews accumulated over five years but only 2 in the last 30 days. The mechanism is compounding: Amazon treats steady arrival of new reviews as a freshness signal and a quality proxy. Big lump-sum review imports (e.g. cramming a Vine campaign into a launch week) underperform spread-out arrival in our panel data. The recommended pattern is even Vine cadence over 60-90 days rather than concentrated launch bursts.