Understanding Retention (www.sequoiacap.com)

While retention is framed primarily as the percentage of users returning to the product itself, it is also useful to understanding specific product features and subpopulations of users. 

For example, you can examine how retention varies by geography, gender or behavioral characteristics (e.g., daytime vs. nighttime use) to paint a clearer picture of your users. Similarly, at the feature level, you can examine how users interact with individual features and then use that knowledge to guide prioritization and the product roadmap.