Basics · also called buyer intent, purchase intent
Commercial intent
Commercial intent is how likely a search or click is to come from someone ready to spend money.
Commercial intent is the money-related slice of search intent. "History of solar power" has almost none. "Solar panel installers near me" has a great deal. Advertisers bid far more for the second, because the person behind it may become a customer worth thousands.
For arbitrageurs, commercial intent decides which topics are worth working on. High-intent subjects such as insurance, loans, legal help and home services carry high click prices and therefore high RPC. Topics with weak intent pay little however much traffic they attract. A vertical is largely chosen on this basis.
There is a trap. A keyword can look commercial on paper while the visitor clicking it has no plan to buy. If a page nudges people toward high-paying keywords they do not care about, the clicks earn well for a short time and then stop converting for advertisers. Google's policies specifically say publisher-suggested search terms must not be designed to generate particular ads, such as ones with a high cost per click. Real commercial intent comes from the visitor, not from the keyword list.
An example
For example, a click on "emergency plumber quote" might earn a publisher $1.20 while a click on "how do toilets work" earns $0.04, because advertisers pay for the first searcher and almost nobody bids on the second.
Related terms
Search intent
Search intent is the goal a person has in mind when they search, such as learning something, finding a website or buying a product.
Keyword
A keyword is the word or phrase that triggers search ads, either typed by a person or passed to the search feed by a web page.
Vertical
A vertical is a subject area or industry, such as insurance, travel or home improvement, that a set of ads and keywords belongs to.
RPC (revenue per click)
RPC is the average revenue earned per monetised (paid ad) click: the "sell" price in search arbitrage. Convert it to revenue per visitor (RPV) before comparing it with CPC.
Forced keywords
Forced keywords are search terms chosen by the publisher, not typed by the visitor, and passed to the search feed to shape which related searches or ads appear.
Keyword stuffing (keyword forcing)
Keyword stuffing in search arbitrage is pushing high-paying search terms onto a page or visitor even though they have little to do with the content or the upstream ad.
Sources: Google AdSense Help: AFS Product-Integrated Feature policies