What is the role of written texts, like biographies, in developing a following for a Sadguru like Sai Baba?

The source material in Chapter 0 explains that a Sadguru accepts service from devotees through books in two primary ways. The first is by creating great works themselves, and the second is by having their biographies written by devoted followers. These biographies, such as the Shri Sai Satcharita by Annasaheb Dabholkar, then become a focal point for the community. As Chapter 0 describes, the congregation of devotees can perform service by engaging in the study and Parayans of these works, which in turn helps them achieve their life's purpose and solidifies their connection to the Guru and each other.