What does "trade area stop share" mean, and how do I compute it?

Trade area stop share is the fraction of all attributed commercial vehicle stops within your queried radius captured by a specific location, a market share proxy for commercial vehicle activity.

Compute it by dividing a location's stopCount by the tradeAreaStopCountTotal field, which is the same for every row in a getPOIAnalytics response. It reflects attributed commercial vehicle stops (roughly 40-50% of all commercial vehicle stops); use it alongside your own transaction data, not as a substitute for it.