Performance marketing, defined.
Atomic definitions of the 37 terms our clients ask about most often. Each entry is written to be useful in 40 seconds and citable as a single answer.
Performance Max
Performance Max (PMax) is Google Ads' automated campaign type that uses Google's AI to serve ads across Search, Display, YouTube, Gmail, Discover, and Maps from a single campaign. It requires the advertiser to upload creative assets and conversion goals; Google's algorithm handles bidding, audience targeting, and placement selection automatically.
Smart Bidding
Smart Bidding is Google Ads' machine-learning bidding system that automatically sets per-auction bids to optimize for a chosen conversion goal. It uses signals like device, location, time of day, audience, and historical conversion data to predict the probability and value of a conversion for every auction.
Offline Conversions
Offline conversions are post-click events (calls, demos attended, deals closed) imported back into Google Ads from a CRM or call-tracking system. They let Smart Bidding optimize for downstream business value — closed-won revenue, qualified pipeline — instead of form-fills that may never convert.
Quality Score
Quality Score is Google Ads' 1-to-10 diagnostic rating per keyword based on three signals: expected click-through rate, ad relevance to the query, and landing page experience. It is a backward-looking calculated metric — improving it requires improving the three input signals; it cannot be set or bid directly.
Customer Match
Customer Match is Google Ads' first-party-data targeting feature that lets advertisers upload hashed customer lists (emails, phone numbers, mailing addresses) to target, exclude, or model lookalikes of those users across Search, YouTube, Gmail, Display, and Shopping. Match rates typically run 40-60% for consumer audiences and 50-70% for B2B/HCP audiences who use professional email addresses consistently.
GCLID (Google Click Identifier)
GCLID is the unique tracking parameter Google Ads appends to ad click URLs (`?gclid=XYZ`) to identify each individual click. Capturing the GCLID in a hidden form field, persisting it through the lead-to-sale lifecycle in a CRM, and uploading it back to Google as an offline conversion is the most accurate way to tie a closed deal to the originating ad click.
Enhanced Conversions
Enhanced Conversions is Google Ads' privacy-preserving conversion-tracking enhancement that sends hashed first-party customer data (email, phone, name, address) alongside the standard conversion event. The hashed data is matched against Google's signed-in user base to attribute conversions that would otherwise be lost to cookie deprecation, iOS tracking restrictions, or cross-device behavior.
Ad Rank
Ad Rank is the value Google Ads calculates for every auction to decide whether your ad shows and in what position. It multiplies your bid by your Quality Score components and factors in the expected impact of ad assets and extensions, the context of the search, and Ad Rank thresholds. A higher Ad Rank can win a better position even at a lower bid than a competitor.
Keyword Match Types
Match types control how closely a search query must align with your keyword before your ad is eligible to show. Google Ads offers three: broad match (widest reach, matches related searches and intent), phrase match (matches queries that include the meaning of your keyword), and exact match (matches the keyword's meaning most tightly). The match type you choose trades reach against precision.
Lookalike / Similar Audiences
A lookalike audience is a targeting segment built by an ad platform's machine learning to find new users who resemble an existing source audience (such as your customer list or website converters). Meta calls them Lookalike Audiences; Google deprecated standalone 'Similar audiences' in 2023, folding the capability into Smart Bidding's automatic optimized targeting.
Negative Keywords
Negative keywords are terms you add to a campaign or ad group to prevent your ads from showing on searches that include them. They are the primary control mechanism for eliminating wasted spend on irrelevant queries, and the discipline that makes broader match types safe to run at scale.
Competitor Conquesting
Competitor conquesting is bidding on a competitor's brand name as a Google Ads keyword so your ad shows when people search for them. It is legal and permitted by Google's policy in most markets — Google restricts trademarks only in ad text, not in keyword targeting. Using the competitor's trademark in your ad copy is a separate question, usually disallowed if they've filed a trademark complaint.
Impression Share
Impression share is the percentage of impressions your ads received out of the total they were eligible for. Google also reports the two reasons you missed the rest: impression share lost to rank (your Ad Rank wasn't high enough) and lost to budget (you ran out of money). It is the clearest measure of how much available demand you're actually capturing.
Auction Insights
Auction Insights is a Google Ads report showing how your performance compares to other advertisers in the same auctions, across six metrics including impression share, overlap rate, position above rate, and outranking share. It reveals who you compete with and whether you're winning, but never their keywords, budgets, or bids.
Target CPA (tCPA)
Target CPA is a Smart Bidding strategy where you set the average cost you're willing to pay per conversion, and Google automatically sets bids in each auction to hit that target across the campaign. It optimizes toward your CPA goal using signals like device, location, time, and audience that manual bidding can't process in real time.
Responsive Search Ads (RSA)
Responsive Search Ads are the standard Google Search ad format: you supply up to 15 headlines and 4 descriptions, and Google mixes and matches them in real time to find the best-performing combinations for each query. RSAs replaced the older Expanded Text Ads as the only standard search format.
Dynamic Search Ads (DSA)
Dynamic Search Ads target searches based on the content of your website rather than a keyword list. Google crawls your pages (or a page feed you supply) and auto-generates the headline and landing page to match relevant queries. The advertiser writes only the description line.
Remarketing (Retargeting)
Remarketing shows ads to people who have already interacted with your site, app, or videos, on Search, Display, YouTube, or Shopping. It re-engages warm audiences who didn't convert the first time. On Search specifically, RLSA (Remarketing Lists for Search Ads) lets you adjust bids or keywords for past visitors who search again.
Local Services Ads (LSA)
Local Services Ads are a pay-per-lead format that appears at the very top of local search results, above standard Google Ads, with a Google Guaranteed or Google Screened trust badge. You pay per qualified lead (a call or message), not per click, and must pass license and insurance verification to run them.
Ad Assets (Ad Extensions)
Ad assets (formerly called ad extensions) are extra pieces of information attached to a search ad, sitelinks, callouts, structured snippets, call buttons, location, price, and promotions. They expand the ad's size and usefulness, and Google shows them when they're predicted to improve performance.
Answer Engine Optimization (AEO)
Answer Engine Optimization (AEO) is the practice of structuring content to be cited as a source in AI-generated answers from ChatGPT, Perplexity, Claude, Gemini, Microsoft Copilot, and Google AI Overviews. Unlike traditional SEO which optimizes for ranking position, AEO optimizes for being quoted within an AI's answer with attribution.
Generative Engine Optimization (GEO)
Generative Engine Optimization (GEO) is the academic term for optimizing content visibility within large language model generated responses, introduced in a 2024 Princeton-led research paper. In practice, GEO and Answer Engine Optimization (AEO) refer to the same discipline, though GEO is more commonly used in research contexts.
E-E-A-T
E-E-A-T stands for Experience, Expertise, Authoritativeness, and Trustworthiness — Google's framework for evaluating content quality, codified in its Search Quality Rater Guidelines. The first 'E' (Experience) was added in December 2022 to specifically reward first-hand experience over second-hand summary.
llms.txt
llms.txt is a proposed standard (analogous to robots.txt) for a markdown file at a website's root that gives large language models a structured summary of the site's content and key pages. The proposal was introduced by Jeremy Howard in September 2024 at llmstxt.org.
IndexNow
IndexNow is an open-source protocol that lets websites instantly notify search engines when content is added, updated, or deleted. It's supported by Bing, Yandex, Naver, Seznam.cz, and Yep — but NOT by Google, which has stated it has no plans to adopt it.
Schema Markup
Schema markup is structured data added to a webpage in JSON-LD, Microdata, or RDFa format that explicitly tells search engines and AI systems what the content is about. The schema.org vocabulary is the standard used by Google, Bing, Yandex, and most LLM crawlers, defining hundreds of types (Article, FAQPage, Product, Organization, Person, etc.).
Google Knowledge Graph
Google Knowledge Graph is Google's structured-data database of real-world entities — people, organizations, places, products — and the relationships between them. Introduced in 2012, it powers Knowledge Panels (the entity cards on the right side of SERPs) and feeds entity-recognition systems used by Google Search, AI Overviews, and Gemini.
Google Business Profile
Google Business Profile (formerly Google My Business) is Google's free local-business listing system that powers the Google Maps panel, the local 3-pack on Search SERPs, and entity verification in the Knowledge Graph. A verified GBP listing is the single highest-leverage local-SEO signal available to a brick-and-mortar business.
YMYL (Your Money or Your Life)
YMYL is Google's classification for content topics that could impact a user's future happiness, health, financial stability, or safety. Pages in YMYL categories — medical advice, financial products, legal information, news on civic events, child safety — are held to substantially higher E-E-A-T standards by Google's Search Quality Rater Guidelines.
Core Web Vitals
Core Web Vitals are three Google-defined page-experience metrics that measure real-user loading speed, interactivity, and visual stability: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS). They became a Google ranking factor in 2021 and are reported in Google Search Console.
Conversion Rate Optimization (CRO)
Conversion Rate Optimization (CRO) is the systematic practice of improving the percentage of website visitors who complete a desired action — submitting a form, booking a call, purchasing a product. Standard CRO methodology: hypothesis → A/B test → measure → ship → repeat, using statistical significance to validate changes.
ROAS (Return on Ad Spend)
ROAS is revenue generated divided by advertising spend, usually expressed as a ratio or percentage. A ROAS of 400% (or 4:1) means $4 of revenue for every $1 spent. It is the primary efficiency metric for e-commerce and revenue-attributable campaigns, and the target Google's Target ROAS Smart Bidding strategy optimizes toward.
Attribution Window
An attribution window (or conversion window) is the period after an ad interaction during which a resulting conversion is credited to that ad. If a user clicks an ad and converts 20 days later, a 30-day click window credits the ad; a 7-day window does not. The window you choose materially changes which channels appear to drive results.
CPC (Cost Per Click)
CPC is the amount you pay each time someone clicks your ad. In the Google Ads auction your actual CPC is usually less than your maximum bid: it is roughly the Ad Rank of the advertiser below you divided by your Quality Score, plus one cent. Average CPC is total cost divided by total clicks over a period.
CPA (Cost Per Acquisition)
CPA is the average amount you pay for one conversion: total cost divided by total conversions. 'Acquisition' means whatever you've defined as a conversion, a lead, a sale, a booked call. It is the core efficiency metric for lead-generation accounts and the target Google's Target CPA Smart Bidding strategy optimizes toward.
CTR (Click-Through Rate)
CTR is the percentage of people who clicked your ad after seeing it: clicks divided by impressions. It measures how relevant and compelling your ad is to the searches it shows for, and it is a direct input into Quality Score through the 'expected CTR' component.
Conversion Rate
Conversion rate is the percentage of clicks (or interactions) that result in a conversion: conversions divided by clicks. It is the clearest measure of how well your landing page and offer turn paid traffic into action, and the lever with the biggest leverage on cost per acquisition.