What is cross-promotion? 

Cross-promotion is a marketing strategy in which app marketers leverage the user base of another app to promote their app. This strategy appears in two forms: 

• Promoting apps in their own portfolio
• Partnering with other app developers

In most cases of cross-promotion, developers promote their apps within their portfolio. This strategy is cost-effective, and sometimes even completely free. 

This type of cross-promotion is especially popular among big mobile game studios. Since they have large user bases across different games, they use this strategy to keep users engaged with their titles.