A categorical description of the perfect company or user that would derive the most value from your product, representing the most efficient acquisition targets.
Why it matters: Targeting outside the ICP increases CAC, drives up churn, and distracts the product team with edge-case feature requests.
In practice: B2B SaaS ICP: 'B2B software companies in North America, with 50-200 employees, using Salesforce, and dealing with compliance issues.'