Advertising terms, explained
Short definitions, no jargon to explain the jargon.
Facts checked 3 Oct 2026 · by the AdSworn team
The short answer
The terms that come up most: CPM is the cost per thousand impressions, CPC the cost per click, CPA the cost per action, CTR the share of views that become clicks, and RPM what a publisher earns per thousand page views. An impression is an ad served; a viewable impression is one that could be seen. Each definition below stands on its own.
Pricing
| Term | Meaning |
|---|---|
| CPM (cost per mille) | The cost per thousand impressions. Price ÷ impressions × 1,000. |
| vCPM | The cost per thousand viewable impressions. |
| CPC (cost per click) | The cost of each click on an ad. Price ÷ clicks. |
| CPA (cost per action) | The cost of each conversion, such as a sale or sign-up. |
| Flat fee | A set price for a placement over a set period, agreed in advance. |
| RPM (revenue per mille) | What a publisher earns per thousand page views. See RPM vs CPM. |
| ROAS (return on ad spend) | Revenue from an ad divided by what the ad cost. |
Measuring
| Term | Meaning |
|---|---|
| Impression | One time an ad was served on a page. |
| Viewable impression | An impression that could be seen: for display ads, at least 50% on screen for at least one second. |
| Click-through rate (CTR) | Clicks ÷ impressions (or views), as a percentage. |
| Conversion | The action you wanted after the click: a sale, sign-up or enquiry. |
| Page view | One load of a page, counted by the site's analytics. |
| Clicks (in Google Search Console) | Times someone clicked through to the page from a Google search result. |
| Impressions (in Google Search Console) | Times a page appeared in Google search results. Not ad impressions. |
| Invalid traffic | Clicks or impressions not from real, interested people: bots, accidental clicks, hidden ads. |
| UTM parameters | Tags added to a link so your analytics shows which ad sent each visit. |
Buying and selling
| Term | Meaning |
|---|---|
| Direct sponsorship | Buying a placement from a publisher at an agreed price and period. |
| Programmatic | Buying ad space automatically, usually by real-time auction. |
| Ad network | A company that sells space on many sites as one product and shares revenue with them. |
| Ad exchange | An automated marketplace where many buyers bid for impressions. |
| Inventory | The ad space a publisher has to sell. |
| Sell-through rate | The share of a publisher's ad space that's actually sold. |
| Publisher | The owner of a website or newsletter that shows ads. |
| Advertiser (sponsor) | The business paying for the ad. |
| Format on “The 12 Best Online Video Editors of 2026 (Free and Paid)” | Advertiser pays | AdSworn (8%) | Publisher gets |
|---|---|---|---|
| Banner ad / 4 weeks | $25 | $2 | $23 |
| Featured post / year | $2,000 | $160 | $1,840 |
Formats and labels
| Term | Meaning |
|---|---|
| Banner ad | A display ad in a set space on the page, labelled "Ad". |
| Native ad | An ad that matches the format of the content around it, labelled "Sponsored". |
| Sponsored post (featured post) | Paid content inside or alongside an article, written to fit it. |
| Contextual advertising | Ads matched to the page's content rather than to the reader's history. |
| rel="sponsored" | A link attribute that tells search engines a link is paid, so it isn't counted for ranking. |
| rel="nofollow" | A link attribute asking search engines not to pass ranking credit through a link. |
| Disclosure | The label that tells readers content is paid, such as "Ad" or "Sponsored". |
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The 12 Best Online Video Editors of 2026 (Free and Paid)
For AI terms such as AI Overviews, GPTBot and llms.txt, see AI search terms, explained.
Straight answers
What does CPM mean in advertising?
Cost per mille: the cost of one thousand ad impressions. A $30 ad shown 2,000 times has a $15 CPM.
What is the difference between CPM and RPM?
CPM is what an advertiser pays per thousand impressions. RPM is what a publisher earns per thousand page views.
What is a good click-through rate?
It depends on the format, page and audience, so compare like with like: the same ad on different pages, or different ads on the same page.
What does rel="sponsored" mean?
It marks a link as paid, which is what Google asks for advertising links, so the link isn't treated as an endorsement for ranking.
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GuideHow online advertising worksSearch, social, display, networks and direct sponsorships: how each way of buying ads works, how it's priced, and how to tell what you actually got.GuideCPM, CPC and CPA: how online ads are pricedWhat CPM, CPC, CPA and flat-fee pricing mean, who carries the risk in each, and how to convert any ad price into a cost you can compare.GuideWhat counts as an ad view?An impression means an ad was served, not seen. The viewability standard, how it's measured, and what to ask any seller before you pay for views.GuideRPM vs CPM: what's the difference?CPM is what an advertiser pays per 1,000 impressions; RPM is what a publisher earns per 1,000 page views. Definitions, formulas and a worked example.