What were the key metrics Instagram's co-founders used to measure success?

Instagram's co-founders, Kevin Systrom and Mike Krieger, used several key metrics to gauge the success of their platform, particularly in the early days:

1. **Daily Active Users (DAUs) and Monthly Active Users (MAUs)**: These metrics were crucial for understanding user engagement and growth. DAUs measured how many unique users were interacting with the app daily, while MAUs tracked engagement over a month.

2. **User Retention Rates**: They monitored how frequently users returned to the app after their first use. High retention rates indicated that users found the app valuable and engaging.

3. **Engagement Metrics**: This included the number of likes, comments, and shares on posts. High engagement rates were a sign that users were actively participating and enjoying the content on the platform.

4. **Growth Rate**: Tracking the rate at which new users were signing up helped measure the app's popularity and the effectiveness of its marketing strategies.

5. **Session Length and Frequency**: The amount of time users spent on the app and how often they used it provided insight into user engagement and satisfaction.

6. **Conversion Rates**: This metric was used to measure how effectively the app could convert new users into regular users and retain them over time.

These metrics helped the co-founders understand how well Instagram was performing and identify areas for improvement, ensuring that the platform could grow and sustain user interest effectively.