Balancing User Experience and Monetization in Mobile Gaming

In mobile game development, how can developers balance a seamless user experience with effective monetization strategies? Discuss different monetization models like in-app purchases, advertisements, and subscription services. What are the pros and cons of each model, and how do they impact player retention? Additionally, how can game designers integrate these strategies without frustrating players or interrupting gameplay? Are there any psychological factors to consider when designing a monetization strategy? What lessons can be learned from successful mobile games in terms of balancing revenue generation with a positive user experience?