EU ad transparency reach

Under the EU's Digital Services Act, very large online platforms must keep a public repository of the ads they show in the European Union. For each ad, the repository includes details such as who paid for it, the period it ran, the main targeting parameters and the total number of people it reached in the EU, often broken down by country.

This reach figure is valuable because it is one of the few public numbers that shows how much an ad was actually shown. Meta publishes it in its Ad Library for ads delivered in the EU, and other large platforms publish similar data in their own repositories.

How to read it:

• Reach counts people, not impressions. One person who saw the ad five times counts once.
• It covers the EU only. An ad that also runs in the United States will reach more people than the figure shows.
• Growth matters more than size. Reach that keeps climbing week after week means the advertiser is still spending.

RivalSonar shows reach where a platform publishes it, next to each ad's active days and an estimated spend. The guide on reading ad longevity and reach goes deeper.