Carrier NAT / multi-family IP pooling

In high multi-family-unit markets and behind carrier-grade NAT, many households share one public IP or egress point, so one lookup result stands in for households spread across a wide area — and the shared point is often far from any of them. Fixed-wireless (5G) home internet adds drift: the household keeps its service while its IP-derived location moves between carrier egress points over time.

Detection

Impression volume per IP far above single-household norms; households whose IP-derived cell moves across periods while the service address has not changed; high fixed-wireless or MDU share in the market.

Mitigation

Treat per-IP household multiplicity as a first-class field where the platform can estimate it
Resolve pooled IPs to an honest wide low-confidence footprint, never to a confident point
Stratify markets on MDU share and fixed-wireless penetration in any design that assigns geography from IP

Detection

Mitigation

Affected conversions