There is no single AI Visibility.

I analyzed 3.7m citations from 20k prompts across ChatGPT, Perplexity, and Google AI Overviews using Omnia data.

Result: only 2.37% of cited URLs appear in all 3 LLMs for the same prompt. 91% live in exactly one.

So, an honest AI Visibility read uses 3 separate numbers:

1. Presence: the share of tracked prompts where your domain appears in any engine.

2. Portability: the share of your cited URLs that appear in all three.

3. Concentration: the share of your citations coming from one engine.

High concentration means your AI visibility sits on a single platform's preferences.

Full analysis in this week's Growth Memo.