Answer Share
The percentage share that a domain or platform occupies in AI answer engines (ChatGPT, Perplexity, Gemini, etc.) through citations, summaries, and recommendations. The primary KPI of GEO tools
What is Answer Share?
Answer Share is the percentage of AI answer engine responses in which your domain appears as a citation, summary, or recommendation when measured across the same query corpus. It is the primary KPI of GEO tools, capturing "the area we occupy in AI answers".
While Answer Inclusion Rate measures simple exposure frequency, Answer Share measures the combined share across citations, summaries, and recommendations. AthenaHQ's 30-day GEO platform test (2026) reported answer-share gaps of up to +46pt between platforms (single source: AthenaHQ 30-Day Test).
Measurement Process
| Step | Description |
|---|---|
| 1. Define query corpus | Build a set of 100~1,000 simulated buyer questions |
| 2. Parallel calls | Issue each query in parallel to multiple LLMs (ChatGPT, Perplexity, Gemini) |
| 3. Citation detection | Detect citations, summaries, and recommendations of your domain in responses |
| 4. Share calculation | (Responses citing us ÷ Total responses) × 100 |
| 5. Trend tracking | Measure Δ answer share over 30-day or 90-day windows |
Practical Interpretation
For Answer Share, trend matters more than the absolute value. Repeating the same query corpus at 30-day intervals reveals the causal effect of GEO actions (Schema, Answer-First, external authority accumulation, entry-point content publishing). Single-shot measurements have low reliability because of LLM response variance.
Aggregate by platform (ChatGPT, Perplexity, Gemini) separately. ChatGPT weights clarity and authority; Perplexity weights sources and real-time information — so the same content yields different shares on different platforms.