Short answer
Measure GEO by how often AI answers name or cite your brand for the questions your buyers ask, compared with competitors, and by what follows: branded searches, referral visits from AI tools and leads. Start with a fixed set of 50 to 100 real buyer questions, check them across ChatGPT, Gemini, Perplexity and AI Overviews every month, and track the trend.
The core metrics:
| Metric | What it tells you |
|---|---|
| Mention rate | Share of tracked questions where AI names your brand |
| Citation rate | Share where AI links to your site as a source |
| Share of voice | Your mentions against named competitors |
| Accuracy | Whether AI describes your offer, locations and prices correctly |
| AI referral traffic | Visits from chatgpt.com, perplexity.ai and similar, in analytics |
| Branded search trend | Whether more people search for you by name |
| Leads and sales | Inquiries and revenue from those visits |
AI answers vary from one run to the next, so measure trends over weeks, not single checks.