What is Share of AI? The competitive KPI explained
Why the raw mention rate deceives
An absolute number like "mentioned in 40% of answers" says little on its own. Is that a lot or a little? It depends entirely on how often the others are mentioned. Share of AI answers exactly this question: of all brands appearing on a topic in AI answers — what share is yours?
How Share of AI is calculated
You define a topic and a set of relevant prompts, run them many times against the AI systems and count the brand mentions. Your Share of AI is your share of the sum of all mentions. Example: if "GEO tools" produces 250 total brand mentions across a hundred answers and 50 of them are you, your Share of AI is 20%. Clean topic scoping and repeated measurement matter, because AI answers fluctuate.
What you use it for
Share of AI turns "how visible are we?" into a competitive question: are we gaining share or losing it? It suits reporting to leadership, benchmarking against defined competitors, and seeing which topics you dominate and where you need to catch up. If your share rises, your GEO work is paying off — regardless of whether clicks follow.
Sources
- Alpar et al.: Generative Engine Optimization, Rheinwerk 2026 (share of voice / competitive share as a KPI).
- Knowhow_GEO_Landwehr.md (Landwehr/Peec AI podcast) — competitive benchmark at the core of prompt monitoring.
How big is your share of AI answers? VISIBILIS measures your Share of AI against the competition in ChatGPT, Gemini and Google AI Overviews and shows which sources the answers come from. Book a free demo
Key takeaways
- Share of AI = your share of all brand mentions on a topic.
- It turns an absolute mention rate into a relative competitive position.
- It's only clean with clear topic scoping and repeated measurement.
- A rising Share of AI is strong proof that GEO measures are working.
Frequently asked questions
Is Share of AI the same as share of voice?
In principle yes — Share of AI transfers the share-of-voice concept from advertising/media presence to brand mentions in AI answers.
Do I need my competitors' data to calculate Share of AI?
No. You evaluate public AI answers; the competitors' mentions are already in them and form the denominator of your share.
What Share of AI value is "good"?
It's relative and topic-dependent. What matters is the trend over time and the gap to the strongest competitor in your topic area, not an absolute threshold.