A working definition
When someone asks ChatGPT, Gemini, Claude, or Perplexity for advice in your category, your LLM visibility is the probability you get named, weighted by how early and how favorably. It is probabilistic because the same question can produce different answers between sessions, which is why single spot-checks mislead and sampled rates are the real measure.
Why it moved to the center of marketing
Buyers now describe situations to language models and act on the names that come back. Our research across 1,200 buyer moments found recommendations forming early in those conversations, before any traditional search happens. A brand with strong rankings and weak LLM visibility is winning a channel buyers are leaving.
What drives LLM visibility
Models synthesize consensus. The inputs they weigh: how consistently the web describes you, review volume and sentiment, presence in the comparison and best-of content they cite, structured data they can parse, and content that answers questions directly enough to quote. None of it is purchasable, all of it is buildable.
How to measure yours
Fix a set of twenty real buyer questions. Run each through the four assistants repeatedly and score mentions, framing, and competitor share. Track it weekly, because model updates rewrite answers without warning. This is the measurement layer Aethon runs continuously, with an LLM visibility tracker built on full conversations rather than keyword prompts.
How to improve it
Work the drivers in order of leverage: sharpen positioning so models can categorize you, publish direct quotable answers to the questions buyers ask, build presence in the citations assistants lean on, and correct stale third-party sources feeding them wrong facts. Then verify the answers moved, because effort that does not change an answer is a cost, not a strategy.