Imagine purchasing a gym membership in order to lose weight or grow more muscular. Having a gym membership is not enough on its own! In order to successfully accomplish that goal, you would need to work out regularly on the right muscle groups. You might have a higher likelihood of success if you participate in exercise classes or hire a personal trainer. Your outcomes are shaped by your own behavior in the gym.
User involvement is defined by the set of user behaviors that lead to experiencing desirable outcomes. If the user's behaviors help them accomplish their goals in using your product, then they have successfully been involved. Improving user involvement enhances the utility of the application through changes in user behavior. The design of your product influences the way users interact with it and their level of involvement. This is illustrated further in The goal of game design is to influence user behavior to create an intended experience.
User involvement is necessary because value creation is a two-way process. In the gym example, the member's involvement in co-creating value is akin to user involvement in a software product. Whether or not we Satisfy the social contract between the user and the app depends on whether we can facilitate that involvement, because the product can't unilaterally provide value to the user upon purchase.
High user involvement means that you've won over your user. They stay loyal to your product for longer, they buy new products you develop, and they speak highly of the product to their friends and contacts. This is sustainable because you have found the way your product fits into user’s lives. With high quality user involvement, people are using your product when it is useful for them. Designing for user involvement has positive effects on adoption, retention, and virality.