> 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/launch/exposure-data/can-i-run-a-brand-lift-without-a-pixel-or-data-exposure.md).
# Can I run a Brand Lift without a pixel or data exposure ?
Pixels or data exposure methods are not mandatory in order to run a Brand Lift. The only requirement is that your campaign has a minimum reach of **100 000 unique users.**
## Why is not mandatory ?
When exposure data is not available, which is fine, we rely solely on the **Ad recall methodology** in order to find respondents.
This methodology rests on asking an ad recall question at the beginning of every survey : **Do you remember seeing this ad ?**
Our method allows us to find people who have really seen the ad and remember it and compare them to those who don’t. Thanks to that, we’ll be able to find the minimum of 250 ad recaller respondents.
## Where can I specify it on Happydemics platform ?
Once you’ve set up and submitted your Brand Lift, click on the **Exposure Data tab** and select **“No exposure data”** for each media.
💡Please note that you have up to **24 hours maximum before answers collection** to add a pixel or an exposure data file if you eventually have it.
👋 If you don't find your answer, feel free to reach out to **** for further consideration.
## 🚀 Related articles
* [Who are our respondents?](/methodology/happydemics-respondents/who-are-our-respondents.md)
* [Audience retargeting](/methodology/happydemics-respondents/audience-retargeting.md)
* [Why do we prioritize ad recall?](/methodology/brand-lifts-by-happydemics/why-do-we-prioritize-ad-recall.md)
* [The benefits of our approach](/methodology/the-benefits-of-our-approach.md)
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