Definition
Buyer intent is what the person asking is trying to decide: understand a category, compare options, judge whether something is worth it, verify trust, or choose what to buy now. In GEO it is attached to each tracked question so results can be read by decision stage.
Why it matters
Being named in research questions and absent from purchase questions is a different problem, with a different fix, than the reverse. A single overall percentage cannot tell the two apart.
How to measure it
Report mention rate grouped by intent, not just overall, and look at the purchase and comparison groups first, since those are the questions closest to revenue.