Myth: use a fresh tracking domain for every campaign to stay safe

The belief: a new domain per campaign isolates risk, so one flag never touches the others. Reality: fresh domains have zero reputation, resolve slowly on first hit, and multiply your cert and DNS maintenance surface.

The correction — domain rotation policy, not domain-per-campaign:
1. Keep a small pool of 3-5 warmed tracking domains, aged 30+ days each.
2. Group campaigns by traffic source onto domains, not 1:1.
3. Rotate a domain out only when it is actually flagged, then quarantine it 90 days.
4. Keep one clean domain in reserve, never used, ready to swap in.

Why domain-per-campaign backfires:
— New domains trigger slower DNS and occasional filtering on first traffic.
— You cannot warm 50 domains; they all stay cold and untrusted.
— Cert renewal across dozens of domains becomes a silent failure source.

Isolation comes from grouping and rotation discipline, not from disposable domains.

Run this before every launch.