How does the act of writing and reading a Guru's biography function as a form of service?

According to the text, a Sadguru accepts service from devotees through books in two primary ways. As explained in Chapter 0, one way is when a devotee writes a detailed, poetic biography of their Guru. This is considered a form of Guru service by the author. This service then extends to the wider community, as other devotees who study and perform devotional readings (Parayans) of the work also gain the merit of serving God in humanity (Jan-Janardan). Through this process, both the writer and the readers are believed to achieve the purpose of their lives.