Ad Word Soup: Decoding the acronyms
Others may go into greater detail, but here's what the acronyms mean that are used in on-line advertising.
CPA - Cost Per Action
CPA is cost per action or payment for when user acts upon an ad
CPC - Cost Per Click
CPC is cost per click or payment for when a click on an ad occurs
CPI/CPM - Cost Per Impression(s)
CPI is cost per impression
CPM is cost per 1000 impressions
CTR - Click Through Rate
CTR is the number of clicks divided by the number of impressions times 100.
It is normally expressed as a percentage. For example,
If 5 people click out of 100 impressions, then the CTR would be 5%.
Fraud is a problem, as well as people gaming the system