# Custom cost model

When Custom cost model is checked you can fix your costs on the calendar manually. To do this select the cost model:

![](/files/-LvIvYjw7CI9gT2ejPD7)

Then **Save** campaign settings. And in the Campaign page grid check saved campaign and click **Edit Daily costs** button:

![](/files/-LvIwuytV2w1aX69B50K)

At this step, you can fix your costs data for a time period. Also, you can specify the type of payment and the cost of the click at which you buy traffic day-by-day. CPC - cost per click, CPM - cost per 1000 clicks. 

When configuration is done click **Save** button.


---

# 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.trackwill.com/campaign/custom-cost-model.md?ask=<question>
```

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.