> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metricanic.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How Metricanic works

> Understand how campaigns connect traffic, destinations, costs, and conversions.

Metricanic connects a visitor's arrival with the destination they see and the events they generate later. This lets you compare traffic sources, ads, landings, and offers using the same visits, costs, and revenue.

A campaign is the connection between these pieces. Creating an offer alone does not start tracking. A campaign needs a traffic source and a working route to an offer, then its tracking link or script must receive traffic.

## Follow one visitor

For a redirect campaign with a landing, the journey is:

```text theme={null}
Ad → campaign tracking link → landing → tracked CTA → offer
                                                       ↓
                                             conversion callback
                                                       ↓
                                            campaign event rules
                                                       ↓
                                                     report
```

Metricanic records the arrival as a **visit** and chooses a destination through the campaign's rotator. A landing's tracked CTA creates an offer **click**. Later, the advertiser or affiliate network sends an event using the Metricanic click ID it received.

The callback does not have to arrive in the same browser session. Its click ID connects the event to the original attribution context. The campaign's event settings decide whether it counts as a conversion and contributes revenue or cost.

With **Direct Script Mode**, the ad opens a configured page directly. The script on that page registers the visit. Choose this when you can install the script on the arrival page. Read [tracking modes](/tracking/modes) before choosing the integration.

## What each element does

| Element           | Purpose                                                                   | Example                                              |
| ----------------- | ------------------------------------------------------------------------- | ---------------------------------------------------- |
| Traffic source    | Defines incoming ad parameters and a source postback URL                  | An ad network that sends creative IDs and click cost |
| Domain            | Provides the hostname for tracking requests                               | `trk.example.com`                                    |
| Campaign          | Connects a source, tracking mode, cost model, event settings, and rotator | A US campaign for a subscription offer               |
| Rotator           | Selects paths, landings, and offers using rules and weights               | Send mobile visitors to a mobile landing             |
| Landing           | Stores the URL of an optional page before the offer                       | A comparison page with a tracked CTA                 |
| Offer             | Stores the destination URL                                                | A signup or purchase page                            |
| Affiliate network | Groups offers and helps pass the click ID to the network                  | The network that reports the purchase                |

Landings and offers are URL records. Your hosting provider or advertiser serves the pages.

## Keep the two click IDs separate

The traffic source may send its own ad click ID. Metricanic stores that as **External ID** and exposes it through `{external_id}` when sending data onward.

Metricanic also produces its own signed `{click_id}`. Pass this value to the offer and have the conversion sender return it unchanged. A campaign ID, an external ad click ID, and a Metricanic click ID are different identifiers.

For example, the ad network sends `extid=ad-123`. The offer receives `subid={click_id}` after Metricanic expands the macro. The offer's conversion callback returns that expanded value. An optional outgoing postback can then return `ad-123` to the traffic source.

## Read the numbers in context

A source ad click usually creates a Metricanic visit. The report's **Clicks** measure tracked offer clicks, so they can differ from the source's ad clicks. A redirect straight to an offer can create a visit without a separate landing click.

An event becomes a conversion through **Count as conversion** in the campaign settings. A signup can be counted as a conversion without revenue. A paid purchase can contribute revenue. Visit costs and included event costs contribute to total cost.

Start with one source, one offer, and one campaign. Complete [your first campaign](/start/first-campaign), then add landings, rotation, and extra events after the basic path works. For an assistant working through the API, use the same concepts with the [AI integration guide](/integrations/ai-agents).