--- title: "What is a fidelity score? | AdBuyMCP" description: "A published score out of 100 answering one question: how much of an audience definition survives translation into a channel's native targeting words." url: "https://adbuymcp.com/glossary/fidelity-score" --- [Home](https://adbuymcp.com/) / [Glossary](https://adbuymcp.com/glossary) / Fidelity score AdBuyMCP's own vocabulary # What is a fidelity score? A published score out of 100 answering one question: how much of an audience definition survives translation into a channel's native targeting words. It describes that translation, so it makes no forecast of reach or performance and says nothing about the quality of the media. [Get my plan and price](https://adbuymcp.com/start) [Book a 30-minute call with the founder](https://adbuymcp.com/contact#book) Free, with no card. We read your homepage, draft who buys from you and show your monthly price before you join the waitlist. Nothing is bought until you've approved the plan and the ads. What it means here ## Here is what the term means for a UK buyer The definition above holds anywhere. Buying media in the UK adds the detail below, including where AdBuyMCP does something different. AdBuyMCP's own term, for the channels in its catalogue. Scores run from 85 on connected TV down to 38 on social at the bottom of its range. Grades run person, household, content, geo-cohort and venue, each one step further from the individual. Four of the catalogue's channels carry a fixed constant (audio 65, addressable TV 55, DOOH 50, cinema 40), because those vocabularies cannot express more however good the brief. The other three vary across three discrete values each: CTV 85, 65, 60; search 82, 68, 45; social 62, 48, 38. Naming a city the UK geography table cannot map costs 15 points on every channel, and the rationale names the city. An awareness plan's price follows the size of your market and how often it should see you, so the score describes how a channel can be aimed rather than what a plan costs. ## How is a fidelity score produced? Each channel has a compiler, and a compiler is a pure function: persona and registry in, targeting specification, fidelity score and lawful-basis manifest out. The same brief produces the same plan every time, which is what makes a plan auditable and a disagreement about it resolvable. A language model extracts the semantics of your brief (geography, seniority, sector, intent topics, exclusions) and never emits a vendor segment identifier. Deterministic registry tables match your terms against catalogue keywords by whole-token overlap and emit only identifiers they hold. On CTV a person-level grade needs at least one strong match, and weak matches produce a household grade and a flag for a person to review. ## What moves a fidelity score? Three things, and the compiler names each one in its rationale or in a warning. The first is the brief, on the channels where it matters: paid search compiles to 82 from buyer-authored intent topics, 68 from interests and 45 from a bare persona label, and the rationale names what is missing. The second is geography the UK table cannot map, which costs fifteen points on every channel and names the city. The third is an exclusion a channel cannot express natively, which drops the overlapping segments and raises a warning naming them. Read the grade before the score, check whether the band is fixed, and use the number to judge how closely a channel can be aimed at your audience. A low score can still be the right buy: cinema's full screen with the lights down has an attention profile nothing else on the list matches. Read next - [Every fidelity band, with a CSV Goes deeper](https://adbuymcp.com/data/fidelity-bands) - [The four channels in an awareness plan Channels](https://adbuymcp.com/channels) - [What UK awareness advertising costs Cost](https://adbuymcp.com/cost) - [What a fidelity score measures Guide](https://adbuymcp.com/guides/what-a-fidelity-score-is) Type your company website or work email to see who we think buys from you and what reaching them 3, 5 or 12 times a week would cost. [Get my plan and price](https://adbuymcp.com/start) Free, with no card. Related terms ## These terms sit next to this one Most confusion in media buying comes from two adjacent terms being used interchangeably, so these are the neighbours worth reading next. - ### [Audience segment](https://adbuymcp.com/glossary/audience-segment) A named group of people a seller will let you target, defined by some combination of demographics, behaviour, stated interest or inferred intent, and identified in a buying system by a specific identifier. - ### [Persona compiler](https://adbuymcp.com/glossary/persona-compiler) The deterministic stage that turns one described audience into the native targeting specification each channel accepts, with a fidelity score and a lawful-basis manifest. Depending on the channel, that specification is segment identifiers, attribute combinations, show allowlists, venue packs or keyword seeds. - ### [Contextual targeting](https://adbuymcp.com/glossary#contextual-targeting) Targeting based on the content an advert appears beside rather than on data about the person seeing it: a show, a genre, a page subject, a venue type. Requires no personal data about the audience. - ### [Lawful-basis manifest](https://adbuymcp.com/glossary/lawful-basis-manifest) A record attached to every compiled channel plan naming each data source used, the lawful basis it relies on, the conditions that come with it, and the warnings raised while compiling. The compiler writes it automatically as it builds the plan. Same group ## These terms are also in AdBuyMCP's own vocabulary These are the terms AdBuyMCP either coined or uses more strictly than the category does. - [Exposure ledger](https://adbuymcp.com/glossary/exposure-ledger) - [Evidence ledger](https://adbuymcp.com/glossary/evidence-ledger) - [Model Context Protocol (MCP)](https://adbuymcp.com/glossary/mcp) [All 81 terms](https://adbuymcp.com/glossary)