# Cost Per Impression (CPI) **Cost per impression(CPI)** is a metric that shows the average cost for a single [impression](/roivenue-resources/glossary/marketing-and-financial-glossary/impressions.md) of your ad. An important reminder: an impression does not equal a view. Indeed, impression only means that the ad was loaded by the promoter’s website. Despite this, CPI is still commonly used to measure the rate you would pay for an online banner ad campaign or other online advertising campaign. ### Parameters **`Calculation:`**` ``CPI = marketingInvestment /` [`impressions`](/roivenue-resources/glossary/marketing-and-financial-glossary/impressions.md) **`Example:`**` ``CPI = 10 000 / 1 000 000 (€) = 0,01 €`**`Unit:`** `Currency` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.roivenue.com/roivenue-resources/glossary/marketing-and-financial-glossary/cost-per-impression-cpi.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.