Signal 01 of 09 · Nebula Diagnostic Spec v1.0.0

Message Match

Does the page promise match the expectation created by the ad or referring source?

Decision rule

The primary headline and first supporting line must restate the same offer, audience, and outcome as the ad or referral context that produced the visit. A run flags this signal when the rendered headline contradicts, generalizes away from, or omits the promised offer.

What the engine inspects

  • ·H1 text
  • ·first subheadline
  • ·title tag
  • ·referring campaign parameters when present

How to check it yourself

  1. Open the ad creative or its final URL parameters beside the live page.
  2. Compare the H1 and first subheadline against the ad promise on three axes: offer, audience, outcome.
  3. Any contradiction, broadening, or omission of the promised offer is a match failure.

The engine automates this inspection and attaches measured evidence to every failing condition. A manual pass is not a substitute for the recorded evidence trail, but it should agree with it.

Pass / fail examples

Pass

Ad promises a free landing page audit. H1 reads "Get a free audit of your landing page" for the same audience. Match.

Fail

Ad promises a free audit. Page opens with generic agency branding and no mention of an audit anywhere above the fold. Flagged.