When analyzing user interactions, what metric might you explore to see usage trends over time?

The metric that would be most effective for analyzing user interactions to see usage trends over time is event volume. This metric provides insights into how many times specific actions or interactions occur within your app or website, allowing you to identify patterns and trends in user behavior over different periods.

Tracking event volume helps you understand engagement and the effectiveness of your content or features. For example, by examining the volume of events related to specific actions (like button clicks, video plays, or form submissions), you can determine which elements resonate most with users. This volume can be viewed over various timeframes (daily, weekly, monthly), enabling you to spot trends such as increased activity after a marketing campaign or a new feature launch.

The other options offer valuable insights but do not directly measure usage trends in the same manner. User retention focuses on how many users return to your site or app after their initial interaction, which is crucial but more about loyalty than ongoing interaction trends. Session duration measures how long users spend during their visits but doesn't reflect the frequency or volume of distinct interactions. Traffic sources provide information about where your users are coming from, which is important for understanding acquisition but does not detail user interaction trends over time.