30-day drop rate
What percent of delivered units (followers / likes / views) have dropped from the recipient account within 30 days of delivery completion. Computed weekly as a 30-day rolling window across that supplier's last 1,000 orders. Lower is better.
Threshold
Target: < 5% drop. Suppliers above 8% on a 30-day rolling window enter probation; suppliers above 12% are immediately demoted.