I measure impact through analytics and user-generated feedback. Some examples and standard metrics illustrated below:

Time since the project started: 5 months; Number of episodes 2; Total number of views: ~500; Total watch time: 21 hours; Total Likes: 23; Total impressions: 3K. One of the most popular and liked content on the Youtube Channel, taking into consideration ~130 other videos. Positive feedback and comments overall, including "Awesome to watch" and "Making it easy to digest". Retention levels match the average for the channel. These videos converted 8 new subscribers directly. Also, the total watch time consists of 60% non-subscribed users, therefore more than half of users are considered a new audience. This proves that Community Stories podcast reaches new users and converts them to subscribers, which is aligned with the goal of the show.