The marketing and AI-search glossary.
Every term an agency will use in a proposal, defined in one paragraph each — no jargon defending jargon. Written to be quoted.
AEO (Answer Engine Optimisation)
The practice of structuring a website so answer engines such as ChatGPT, Perplexity, Claude and Google AI Overviews can extract and cite it. It relies on factual, self-contained statements, schema markup, and crawler access rather than keyword density.
GEO (Generative Engine Optimisation)
Optimising for visibility inside generated answers rather than ranked links. GEO focuses on being the source a model quotes: entity clarity, corroboration on third-party sites, and quotable statistics with dates and units.
llms.txt
A plain-text file at the site root that summarises an organisation's key facts, pages and quotable answers for language models. It complements robots.txt, which controls access, by supplying context.
Citation tracking
Measuring how often a brand is named or linked inside AI-generated answers for a fixed set of prompts, tracked over time per engine. It is the AI-search equivalent of rank tracking.
Entity SEO
Building a machine-readable identity for a brand — consistent name, address, founders and sameAs links across schema, Wikidata, directories and press — so search and answer engines treat it as one known entity rather than scattered strings.
Schema markup
Structured data in JSON-LD that labels page content — Organization, Service, FAQPage, Article, Product — so machines can parse meaning instead of inferring it from layout.
Core Web Vitals
Google's user-experience metrics: Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness) and Cumulative Layout Shift (visual stability). They are a ranking input and a conversion factor.
Technical SEO
The crawl, index and render layer: sitemaps, canonicals, status codes, internal linking, JavaScript rendering, hreflang and site speed. It sets the ceiling that content and links can reach.
Programmatic SEO
Generating many pages from a structured dataset — cities, categories, comparisons — each with genuinely distinct data. Done without unique data, it is thin content and gets filtered.
SERP
Search Engine Results Page. In 2026 a SERP commonly includes an AI Overview, a map pack, People Also Ask, ads and only a handful of classic blue links.
CAC (Customer Acquisition Cost)
Total sales and marketing cost divided by new customers acquired in the same period. Blended CAC includes organic; paid CAC isolates media-driven acquisition.
LTV (Lifetime Value)
Total contribution margin a customer generates across their relationship with the business. Useful only when paired with CAC and a payback period.
LTV:CAC ratio
Lifetime value divided by acquisition cost. Around 3:1 is a healthy target for most D2C and SaaS businesses; far above it usually means underinvestment in growth.
CAC payback period
Months of contribution margin needed to recover acquisition cost. For Indian D2C, under 3 months is strong; for B2B SaaS, under 12 months is workable.
ROAS
Revenue divided by ad spend for a channel or campaign. Revenue-ROAS flatters performance; contribution-margin ROAS, which nets out COGS, shipping and returns, is the honest version.
MER (Marketing Efficiency Ratio)
Total revenue divided by total marketing spend across every channel. It survives attribution loss because it needs no per-click tracking.
Incrementality
The revenue a channel actually caused, measured by holdout or geo tests, as opposed to revenue it merely reported. Retargeting is the classic case of high reported and low incremental value.
Attribution
The model assigning credit for a conversion across touchpoints — last-click, data-driven, or media-mix modelling. Every model is a simplification; pick one and read it consistently.
Server-side tracking
Sending conversion events from your own server to ad and analytics platforms instead of from the browser, which improves data quality where browser tracking is blocked.
CPM
Cost per thousand impressions — the price of reach. Rising CPMs usually signal auction competition or narrow targeting, not weak creative.
CPC
Cost per click. In Indian search auctions it varies enormously by category, from a few rupees in broad ecommerce to several hundred in legal, insurance and education.
Creative fatigue
The decay in performance as an audience sees the same asset repeatedly, visible as falling click-through and rising CPA at stable spend. The fix is new concepts, not new colours.
Full-funnel media
Deliberately splitting budget across awareness, consideration and conversion, so retargeting and branded search have new demand to convert rather than harvesting existing intent.
Retainer
A recurring monthly fee covering a defined scope of agency work. It buys capacity and continuity; it does not buy guaranteed outcomes, and any agency promising both is mispricing one of them.
Media management fee
The agency charge for running paid media, usually 12–18% of spend or a flat retainer at lower spend levels. It is separate from the media budget itself.
Anti-list
A published list of work an agency refuses to take on. It is a trust signal: refusals are verifiable in a way that capability claims are not.
Now use the terms against us.
Ask any agency — including this one — for contribution-margin ROAS, a link log and a citation report. The answer tells you everything.
Talk to Magnum Radius →