What are the two forms of service a Sadguru accepts from devotees in relation to books and literary works?

As detailed in Chapter 0, a Sadguru takes two distinct types of service from devotees through books. The first method involves the Sadguru creating monumental works themselves, with examples being Shri Dnyaneshwari, Shri Nath Bhagavata, or Shri Dasbodh. The second method is when the Sadguru inspires his devotees to write his biographies. Through this act, the Sadguru accepts service not only from the writer but also from the congregation of devotees who engage with the text through study and Parayans, thereby helping them achieve the purpose of their lives.