The most common methods are for clicks and impressions.
In the first case, each user click on an advertisement is paid for.
When paying according to the second model, the price is indicated per number of impressions.
In some advertising tools, payment is available for completing cryptocurrency data a target action: purchasing a product, placing an order, etc.
Geography
By targeting your ads to a specific region or locality, you filter out unnecessary audiences and thus save your advertising budget. Why show ads with service station services in Kharkov to people who live in Kyiv? Everything is logical here.
Targeting
Setting gender, age, interests and other parameters of the target audience is another way to save. Advertisements will be shown only to the audience that is potentially interested in your offer.