Can you elaborate on the philosophy of a Sadguru accepting service through literary works and how this builds a devotee community?

According to the philosophy outlined in Chapter 0, a Sadguru takes two types of service from devotees through books. The first is when the Guru authors a great work themselves, and the second is when they have their biographies written through devotees. This latter method creates a powerful vehicle for community building. The devotee-author performs a service by writing the biography, like the Shri Sai Satcharita. Subsequently, the Sadguru accepts service from the wider congregation of devotees who engage in the study and Parayan of that text. This collective act of devotion serves the Guru, benefits the individual, and forges a strong spiritual community.