How to measure performance in AI search reliably.

Share of voice and mention tracking is what everyone does. But LLM answers are non-deterministic — they change every time you ask. LightSite sits on your website and measures two events that actually happened: AI bot visits, and human visits from AI assistants. Together they give you a metric you can trust — AI CTR.

Two events you can actually count

AI bot visits. When someone asks ChatGPT, Claude, Perplexity, or Gemini about your category, the assistant often verifies a fact by fetching your site. GPTBot, ClaudeBot, PerplexityBot, and Google-Extended each show up in your logs. Every hit is proof you were considered.

Human visits from AI assistants. After the assistant answers, some users click through. They arrive with a referrer that ties back to the assistant. Standard analytics miss most of these because the referrer is stripped or classified as "direct".

The metric: AI CTR

AI CTR = Human AI visits ÷ AI bot impressions. It is the share of AI attention that turned into a real click. Deterministic, because both sides are events you can count.

What our data tells us about what works

  • AI visitors land on answer-first pages — comparisons, use cases, pricing explainers, alternatives — not on the homepage.
  • Reddit and LinkedIn campaigns move AI discovery bots roughly 37% harder on average than comparable PR-led campaigns.
  • High bot activity with flat human AI clicks means you were considered but not recommended — a trust or positioning gap.

FAQ

Why isn't share of voice enough? LLM answers are non-deterministic. The same prompt can return a different answer based on model version, timing, personalization, and retrieval. Mention counts are directional, not attribution.

What are AI impressions? Verified AI bot sessions on your website — GPTBot, ClaudeBot, PerplexityBot, Google-Extended, and other AI fetchers.

What counts as a human AI visit? A real person arriving from ChatGPT, Claude, Perplexity, Gemini, or Google AI Overviews.

How is AI CTR calculated? Human AI visits divided by AI bot impressions, normalized by bot session, platform, page type, and time window.

Does more bot traffic always mean better visibility? No. A spike in AI bots means you were considered. Only humans arriving from AI assistants confirms you were recommended.