devtodev lead analyst Vasiliy Sabirov tells everything you always wanted to know about retention but were afraid to ask: 1. What is the retention and how it is measured. Review of existing retention calculation methods. 2. What is the perfect retention? Examples from the industry. 3. What determines the retention? Free / paid traffic, different platforms, even the days of week. 4. What depends on retention. How retention is connected with another KPI and primarily KPI. 5. How to improve retention? Different cases from those projects who increased their retention values.