Co-mention
A co-mention is an AI answer that names your brand and a competitor together, so the buyer sees both on the same shortlist.
A co-mention is an AI answer that names your brand and a competitor together. When ChatGPT or Perplexity answers "best payroll software for a small agency" with a list of four brands, each pair on that list is co-mentioned, and the buyer sees them side by side.
Why it matters
Co-mentions show who you compete with in AI answers, which may differ from the list your sales team uses. They also expose the more urgent case: answers that name a competitor and leave you out. For each competitor, compare two rates:
- Appears with you: the share of its answers in which you are named too.
- Appears without you: the share of its answers in which you are missing.
A competitor that appears without you in most of its answers is being named in conversations you are not part of. PromptSignal reports this as co-mention threat for every competitor you track.
How to measure it
Count over many runs, not one answer. In a 2026 SparkToro study, ChatGPT, Claude and Google's AI Overviews or AI Mode returned the same list of brands less than once in 100 runs, so the brands that share an answer change from run to run.
Example: across 50 runs, a competitor is named in 34 answers, and you are named in 14 of those 34. It appears with you in 41% of its answers and without you in 59%. List the prompts behind the 20 answers without you, then read the pages they cite: the citation gaps there are your first fixes. Track share of voice alongside, since it shows how mentions split across all the brands you track.