> For the complete documentation index, see [llms.txt](https://support.happydemics.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.happydemics.com/methodology/happydemics-respondents/audience-retargeting.md).

# Audience retargeting

In some cases—depending on the media and setup of your campaign, it’s possible to **target respondents likely to have been exposed to your campaign**. This can be done by providing us with **exposure data** such as tracking pixels, user IDs, broadcasting framework or geolocation data. You can go to the dedicated section for more information.

That said, **exposure targeting is entirely optional**. Even without it, we’re able to gather a reliable sample of **250 respondents who recall seeing or hearing your ad** and 250 who don’t. This split allows us to measure the impact of your campaign using our methodology.

<figure><img src="https://4099963361-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQJVhUYUj85xxjSZPjYIM%2Fuploads%2F7q3Srd0COdkaVK82cA19%2FThe%20use%20of%20exposure%20data.png?alt=media&amp;token=99dc3cd4-6f86-4adc-a3b2-04426a616634" alt=""><figcaption></figcaption></figure>