You should use Unique Reach and Frequency to measure how many people were served your ads and how many times they were each served across devices and formats in addition to fundamental video metrics like “Video played to”.
- You should use Unique Reach and Frequency.
- You should use Viewability with Active View.
- You should use Brand Lift.
- You should use Reach Planner.
The correct answer is: You should use Unique Reach and Frequency
Explanation: To measure the reach and frequency of your Google Video campaign, unique reach and frequency metrics are a great solution. These metrics take into account cross-device usage and co-viewing to give you a more accurate view of your campaign’s performance. Metrics such as unique users, average impression frequency per user, and frequency distribution can be added to your statistics table and scoped to only view video campaigns. Google Ads uses statistical models to deduplicate an audience across different devices and networks, resulting in the number of unique users who saw your ad.
Read more here: https://support.google.com/google-ads/answer/2472714