Confirmed: pruning 40% of seller IDs lifted CPMs 18%

Confirmed: pruning 40% of seller IDs lifted CPMs 18%
A mid-size sports publisher we track audited their sellers.json footprint across 14 SSPs.
— Found 240+ seller account IDs, 96 with zero spend in 90 days
— Killed dead reseller paths, kept 11 direct + 3 high-fill resellers
— Demand collapsed to 6 clean paths buyers could actually trust
Result over 6 weeks: programmatic CPMs up 18%, bid density per impression up from 4.1 to 6.7 because DSPs stopped deduping fragmented supply.
Impact: Path consolidation is yield, not hygiene theater.
Confidence: sourced