PPC Terms & Definitions

In PPC advertising, ad placement and pricing are decided through an automated, real-time electronic auction. Rather than awarding the spot to the highest bid alone, the platform combines an advertiser’s bid with quality signals (expected click-through rate, ad relevance, landing page experience) to calculate an “Ad Rank” or similar score, which determines both whether an ad shows and what it costs.

Ad extensions, called ad assets in Google Ads, are additional pieces of information that may appear with an advertisement. Examples include phone numbers, sitelinks, callouts, locations, prices, and promotions. Assets can make an ad more useful and prominent, but the platform determines when eligible assets appear.

Google introduced AI Max for Search campaigns in 2025 as an optional collection of AI-powered features designed to expand reach, automate ad messaging, and improve campaign performance.

AI Max isn’t a new campaign type; it’s a set of additional capabilities that advertisers can enable within existing Google Search campaigns.

Attribution is the method used to determine which advertising interaction receives credit for a conversion. This is especially important when a customer interacts with multiple ads, campaigns, devices, or marketing channels before converting. Click attribution focuses specifically on eligible ad clicks.

A bidding strategy in which the platform’s algorithms set and adjust bids on the advertiser’s behalf — using signals like device, location, time of day, and audience — in order to hit a specific performance goal, rather than the advertiser setting bids manually for each keyword or placement.

In a shopping or product feed, the brand attribute identifies the manufacturer or recognized brand associated with a product. In broader PPC terminology, brand can also refer to an advertiser’s company, product, or trademarked name. Brand searches are often managed separately from non-brand searches because performance and intent can differ.

A callout is a short, non-clickable piece of text that may appear with a search ad. Callouts highlight additional selling points such as “Free Shipping,” “24/7 Support,” or “No Long-Term Contract.” They should be concise, specific, and different from the main ad copy.

CPA stands for Cost Per Acquisition or Cost Per Action. It measures the average advertising cost required to generate one tracked conversion. CPA is calculated by dividing total campaign cost by the number of conversions. It should be reviewed alongside conversion quality, value, margins, and close rates.

CPC stands for Cost Per Click. It is the amount an advertiser pays when someone clicks an advertisement. CPC can refer to the actual cost of an individual click or the average cost across multiple clicks. A lower CPC does not automatically mean better performance because traffic quality and conversions also matter.

Expanded Text Ads (ETAs) were a Google Search ad format featuring three headlines and two descriptions. Advertisers controlled the copy, unlike today’s Responsive Search Ads. Google discontinued ETA creation and editing in June 2022.

PPC fault monitoring is the ongoing, often automated tracking of a pay-per-click account for technical breakdowns that quietly waste spend or degrade performance — things like disapproved ads, broken landing page links, conversion tracking failures, expired payment methods, or budget caps hit early in the day. Its purpose is to catch and flag these issues in near real time, before they burn through significant budget or leave campaigns running with no way to convert traffic.

The Google Merchant Center (GMC) is an intermediate account that serves as a database store for an advertiser’s eCommerce account. The source of the data is a merchant’s account on an eCommerce platform (e.g. Shopify, BigCommerce, WooCommerce, etc). The Merchant Center provides product data to the merchant’s PPC campaigns in Google or Microsoft Ads accounts. Because a lot of different eCommerce platforms and implementations are used to build and host stores, the GMC

GTIN stands for Global Trade Item Number. It is a standardized product identifier used across manufacturers, retailers, marketplaces, and advertising platforms. UPC, EAN, JAN, and ISBN identifiers are forms of GTINs. When a valid GTIN exists, it should be submitted accurately in the product feed.

The web page traffic lands on.  In paid search, this is the page a PPC campaign is driving traffic to. The content of a landing page is crafted to deliver the most relevant information, and the behavior of traffic visiting the page is tracked to measure performance.

The time during which an automated bidding algorithm collects performance data on a campaign in order to learn when to bid more or less aggressively; performance is often volatile during this window and typically stabilizes once it ends.

A subset of artificial intelligence in which an algorithm improves its performance on a task — such as bidding or ad targeting — by identifying patterns in historical data, rather than following fixed rules set manually by a person.

MER is calculated the same way as ROAS (Conversion Value ÷ Ad Spend) but better reflects what the metric actually represents: a ratio of ad spend efficiency rather than a “return.” We often use MER instead of ROAS, since it avoids the misleading implication that the metric itself is the return — that’s NAC’s job.

MPN stands for Manufacturer Part Number. It is an identifier assigned by the original manufacturer to distinguish a specific product or component. A reseller should not create a new MPN for an existing manufacturer’s product. Accurate MPN and brand information can help advertising platforms identify products.

NAC is the dollar amount of profit contribution generated by an ad campaign after subtracting ad spend from conversion value, calculated as Conversion Value − Ad Spend. Unlike ROAS, NAC shows the real financial return in dollars, making it the more meaningful measure of a campaign’s bottom-line impact.

PPC stands for Pay Per Click advertising. The term originated when advertisers commonly paid for each individual ad click. Today, PPC is often used more broadly to describe paid digital advertising, including campaigns charged by clicks, impressions, video views, engagements, or conversion actions.

A product feed is a structured file (commonly CSV or XML) listing every SKU an eCommerce seller offers, along with attributes like title, price, availability, and images. Platforms such as Google Shopping, Meta, and online marketplaces pull directly from this feed to list, match, and display products to shoppers.

Google’s auction algorithm is fundamentally built on relevance. Quality Score (QS) is a metric assigned at the keyword level, that reflects ad relevance, expected click-through rate, and landing page experience. It’s assigned on a scale of 1 to 10. It’s a measure of how relevant the associated ad(s) and landing page experience is to the keyword.

ROAS measures the ratio of revenue generated to every dollar spent on advertising, calculated as Conversion Value ÷ Ad Spend. As a ratio rather than a dollar figure, it reflects the efficiency of ad spend, not the actual profit or “return” the name implies. See the related term, MER.

A clickable link to a specific page on an advertiser’s website — beyond the main landing page — that appears below a text ad, giving users a shortcut to relevant content such as “Pricing” or “Contact Us.”

SKU stands for Stock Keeping Unit. It is an internal identifier created by a merchant, retailer, or inventory system to track a specific product, variation, size, color, or configuration. Unlike a GTIN, UPC, or MPN, a SKU is not a standardized global product identifier.

Target CPA is an automated bidding goal that instructs the platform to pursue conversions at an average cost per acquisition near the advertiser’s selected target. Individual conversions may cost more or less than the target. Setting an unrealistic target can restrict traffic and reduce available conversion volume.

A form of automated bidding wherein the objective is to bid in a way that achieves, on average, a pre-defined target return on ad spend (revenue generated per dollar spent).

UPC stands for Universal Product Code. A standard UPC-A is a 12-digit barcode identifier used primarily in North America to identify a commercial product. A UPC is also known as a GTIN-12 and should be taken from the product or its packaging rather than created by the merchant.

A view-through conversion occurs when someone sees an eligible advertisement, does not click it, and later completes a tracked conversion within the platform’s defined conversion window. View-through conversions should be evaluated separately from click-through conversions because an ad view does not show the same level of direct interaction as a click.