A broken tag fails silently — catch it before launch, not after.

• The conversion pixel fires once per conversion — not on every page load or refresh.
• Tags fire on the actual confirmation event (order confirmed, form submitted), not just on load of a URL that could be reached without converting.
• A test conversion was run this month and verified in the platform's own reporting — not assumed from a tag debugger looking right.

• Dynamic macros ({click_id}, {campaign_id}, {creative_id}, etc.) resolve to real values in the fired pixel, not literal unresolved placeholder text.
• Currency and value macros pass the actual transaction amount, not a hardcoded number left over from testing.

• The click-tracking URL redirects to the final landing page without an extra visible hop that adds load time.
• Click IDs are captured and passed through to the landing page for attribution — not dropped at the redirect.
• Click-tracking URLs are HTTPS, not HTTP — mixed content gets silently blocked by some browsers.

• A third-party viewability vendor, or an MRC-accredited platform measurement, is in place before optimizing on it.
• Viewability thresholds match the MRC standard: 50% of pixels in view for at least 1 continuous second for display, 2 seconds for video.
• Attention or brand-lift metrics, if used, are cross-checked against a second source before being trusted on their own.

• A brand safety and suitability vendor, or platform-native controls, is active — not left on default settings.
• The blocklist or exclusion list has actually been reviewed this quarter, not set once at launch and forgotten.

• VAST tags were run through a tag validator before launch — a broken VAST tag fails silently and simply doesn't serve.

This confirms the plumbing is correct, not that the campaign will perform. A tag that fires correctly on junk traffic is still a tag that fires correctly — QA and performance are two separate questions.