Digital Advertising Glossary: CPC, ROAS, PMax and More, in Plain Language
A short, plain-language glossary of the terms that come up in every conversation about digital advertising: costs, metrics, campaigns and tracking. Each term is explained in a sentence or two, and some link to the full guide.
Metrics and costs
CPC (Cost Per Click)
What each click on your ad costs. On Google and Meta the price is set in an auction, so it changes with competition and ad quality. A cheap click isn't necessarily a good one: what matters is the cost of a lead or a sale. How much Google Ads costs →
CPM (Cost Per Mille: cost per thousand impressions)
What it costs to show an ad a thousand times. It's the basis of Meta pricing, and a good way to see how expensive it is to reach a given audience. How much Facebook ads cost →
CPL (Cost Per Lead)
What each inquiry costs: a form, a message or a call. For service businesses this is the number to watch most closely, along with lead quality.
CPA (Cost Per Acquisition)
What each sale from your ads costs. For online stores, this is the number that decides whether a campaign is profitable.
CTR (Click-Through Rate)
The share of people who clicked your ad out of those who saw it. A high CTR usually means the ad is relevant to its audience.
ROAS (Return On Ad Spend)
How much revenue came back for every shekel spent on ads. A ROAS of 5 means ₪5 in sales for every ₪1 spent. It isn't profit: product and operating costs still come off.
Conversion rate
The share of visitors who took the action you wanted, like leaving their details or buying. Improving a landing page's conversion rate can save a big part of the budget. The full calculation →
Campaigns and audiences
Quality Score
Google's rating for a keyword, based on expected click-through rate, ad relevance and landing page experience. A higher score can lower your cost per click.
Negative keywords
Words that stop your ad from showing on irrelevant searches, like "jobs", "free" or "course". One of the simplest ways to save budget on Google.
Impression share
The percentage of relevant searches where your ad appeared. A low share usually means the budget runs out early or your bids are too low.
Smart Bidding
Google strategies that automatically set how much to bid in each auction, based on the chance of a conversion. They only work well when tracking is accurate and there are enough conversions.
Performance Max
A Google Ads campaign type that advertises across all of Google's channels from one campaign: Search, Shopping, YouTube, Gmail and Maps. When it works and when it doesn't →
Remarketing
Showing ads to people who already visited your site or showed interest, but didn't leave details or buy. Usually one of the most cost-effective audiences.
Lookalike audience
An audience Meta builds from people similar to your customers, for example to a customer list or to people who left details on your site.
Learning phase
The period when ad platforms test audiences and ads after a launch or a big change. Results are less stable during it, so it's best not to change everything every couple of days.
Tracking and data
Conversion / key event
An action that matters to the business: a form, a call or a purchase. In GA4 it's now called a "key event"; in Google Ads it's still a "conversion". Why GA4 shows no conversions →
GA4 (Google Analytics 4)
Google's tool for measuring traffic and actions on your site: where visitors came from, what they did, and which channels brought leads and sales.
Meta Pixel
A small piece of code on your site that tells Meta about actions like leads and purchases, so the system learns who to show your ads to. The pixel guide →
Conversions API (CAPI)
A connection that sends events to Meta from your site's server, not only from the browser, so leads and purchases the pixel misses still get counted. The CAPI guide →
UTM (Urchin Tracking Module)
Tags added to a link that record which campaign, source and ad each visitor came from. Without them, some traffic shows up in GA4 as "direct".
Attribution
The method that decides which channel gets credit for a conversion when a customer saw several channels along the way. It's one reason numbers in Google, Meta and GA4 rarely match exactly.
Consent Mode
A Google setting that respects each visitor's cookie choice, while still allowing limited, anonymous measurement when they decline.
Budget and management
Media budget
The money paid directly to Google or Meta for advertising. It's separate from the management fee. Budget calculator →
Management fee
Payment to whoever builds and runs the campaigns: strategy, ads, tracking, optimization and reporting.
Landing page
The page people reach after clicking an ad. A fast, clear page with a short form affects cost per lead more than almost any campaign change.
Business portfolio (Business Manager)
Where a business manages its pages, ad accounts and pixel on Meta. It should be owned by the business, with the agency added as a partner. Who owns your ad account →