Check this page with an assistantOpens a chat asking it to summarise this article and name the evidence behind each claim.

Claude opens with the prompt on your clipboard: Anthropic does not support prefilled prompts on the web, and we would rather copy it than ship a button that drops it.

The Metric, and Why It Is Not a Ranking

Share of model asks a single question: when a buyer describes their problem to an assistant without naming any vendor, how often does your name come back? It is a mention rate across a fixed set of questions, not a position in a list, and treating it as a ranking is the first mistake people make with it.

The distinction matters because there is no stable list to be ranked in. Ask the same assistant the same question five times and you may get five overlapping but different sets of names, in different orders, with different reasoning. There is no tenth blue link to climb toward. What exists is a probability that you appear, and the only honest way to observe a probability is to sample it repeatedly.

That framing also sets the ceiling on what the number can support. Share of model cannot be attributed to revenue, cannot be segmented by buyer, and moves for reasons entirely outside your control, including model updates that reshuffle everything overnight. It answers one question well: are we in the consideration set that assistants draw from? That is worth knowing, and it is all it is worth.

Designing the Prompt Set

Fifteen to twenty-five questions, written the way a buyer would actually ask them, covering the range of intents that precede a purchase in your category. Never include your brand name in a prompt. The moment you do, you are measuring whether the assistant knows you exist, which is a different and much easier question.

Build the set from real language rather than keywords. Sales call recordings, support tickets, and the questions people email you are better sources than a keyword tool, because assistant queries are longer, more conversational, and carry constraints that keyword research strips out. "Best CRM" is a keyword. "We're a five-person agency outgrowing spreadsheets and I need something my team will actually use" is a prompt, and it is the second one that reflects how these tools are used.

Prompt typeExample shapeWhat it tests
Open categoryWho should I look at for X?Whether you are in the default consideration set
ConstrainedX for a team of five with no technical staffWhether your positioning survives a qualifier
ComparativeAlternatives to the category leaderWhether you register as a credible substitute
Problem-firstA description of the symptom, no category namedWhether you are connected to the problem or only the label
Local, if relevantX near a named place, with a constraintWhether your local presence is legible

Freeze the set once written. Every prompt you change is a break in the trend line, and the temptation to tweak wording after a disappointing month is exactly how these logs become useless. If a prompt genuinely needs to change, add it as a new one and keep the old one running until you have a year of both.

Running It Without Contaminating the Result

Clean sessions, five runs per prompt per assistant, same week each month, logged immediately. The contamination risks are personalisation, memory, and your own location, and all three inflate your numbers in the direction you would like them to go.

  1. Use logged-out or fresh sessions.

    An account that has discussed your company before will mention your company more. Assistant memory and chat history are the single biggest source of false optimism in DIY measurement, and the person running the test is always the most contaminated account available.

  2. Run each prompt five times, separately.

    New conversation each time, not five messages in one thread. A follow-up in the same thread inherits everything above it, so you would be measuring the conversation rather than the model.

  3. Log four fields per run.

    Was your brand named, which competitors were named, in what order, and which sources were cited if the assistant showed them. The citation field is the most actionable one, because it tells you which third-party pages are doing the work.

  4. Hold the calendar steady.

    Same week, same assistants, same prompts. Model releases land unpredictably and will move your numbers on their own; a consistent schedule at least stops you adding your own variance on top of theirs.

  5. Record the date and model version.

    When a number jumps, the first question is whether the model changed. Without a version note you will spend a week looking for a cause on your own site that was never there.

Reading the Result, Including the Error Bars

With twenty prompts and five runs across three assistants you have three hundred observations, which is enough for a coarse rate and nowhere near enough for a precise one. Report it as a fraction with the sample size attached, and treat month-to-month moves of a few percentage points as noise until proven otherwise.

Expect large differences between assistants, and do not read them as performance differences on your side. Third-party analysis of AI responses has reported that different systems name brands at very different rates overall, with some mentioning brands in nearly every response and others in around half. If one assistant names you far less than another, the likeliest explanation is that it names everyone less, which is why comparing your share against competitors within the same assistant is the only comparison that means anything.

Sentiment is worth logging and rarely worth worrying about. The same body of analysis found the overwhelming majority of brand mentions were neutral in tone, with a small positive minority and a very small negative one. If you find a genuinely negative characterisation repeating across runs, that is a real signal worth chasing to its source. A single unflattering sentence in one run is not.

The honest report

"Named in 34% of 300 observations across three assistants in July, against 41% in June, on an unchanged prompt set." Not "our AI visibility dropped 17%".

What Moves It, and What Only Appears To

Share of model responds to the same things that make a brand legible to any researcher: consistent identity across the web, third-party corroboration on sources assistants retrieve, and content that answers the constrained question rather than the generic one. It does not respond to files nobody reads.

The citation field in your log is the fastest route to the actual levers. Over a few months it will show you which sites assistants keep reaching for when they answer your category question, and those sites are usually review platforms, directories, and reference pages rather than vendor sites. That matches the broader citation research discussed in comparison and alternatives pages, and it points the work off your own domain more often than agencies selling on-site optimisation would like.

What does not move it: llms.txt, for which no consumption evidence exists, as documented in our review of the file; schema markup added to content that is not otherwise credible; and volume of publishing. What does, in the order we see it hold up, is being indexed at all, being structured so a specific answer is extractable, and being described consistently wherever your name appears. The full sequence is in the AI search visibility playbook.

Questions People Ask About Share of Model

What is share of model?

Share of model is how often an AI assistant names your brand, relative to competitors, when someone asks a general question in your category. It is the assistant-era counterpart to share of voice: not whether you can be found when someone searches your name, but whether you get mentioned at all when nobody has named anyone yet.

How do I measure share of model without a paid tool?

Write a fixed set of category questions a buyer would actually ask, run each one several times in a clean session on each assistant you care about, and log which brands were named and in what position. Repeat monthly without changing the prompts. The discipline that makes it meaningful is the fixed prompt set and repeated sampling, not the software.

Why do I get different answers to the same question?

Because these systems are not deterministic, and several layers of variation stack: sampling randomness in generation, retrieval that may pull different sources on different runs, personalisation from account history, and model updates between sessions. A single run tells you almost nothing. This is precisely why repeated sampling is the core of the method rather than an optional refinement.

How many times should I run each prompt?

Five runs per prompt per assistant is a workable floor for a small business, and more is better if the answers are unstable. The signal you are looking for is a mention rate, so a single run gives you a binary with no confidence attached, while five gives you a coarse fraction you can track. If your rate swings wildly between months at five runs, increase the count before you conclude anything changed.

Is share of model worth tracking for a small business?

It is worth tracking cheaply and worth being sceptical about. The number cannot be tied to revenue, it moves for reasons outside your control such as model updates, and it invites over-interpretation. Tracked as one row in a monthly sheet alongside impressions and referrals, it is useful context. Treated as a KPI to optimise, it becomes a way to spend money on something you cannot verify.

Primary Sources

SearchHandled Editorial TeamPublished Nov 3, 2025 · Last reviewed Nov 3, 2025. Every factual claim is checked against the linked primary sources; corrections can be submitted through our contact page.