From the perspective of the Guru, what is the value of devotees reading books about them?

The source material explains that a Sadguru takes service from devotees through books in two primary ways. As outlined in Chapter 0, one method is by having his biographies written by his devotees. The Guru then accepts service in the form of study and Parayans from both the writer and the wider community of devotees. The value in this is that it enables the devotees to 'achieve the purpose of their lives.' By facilitating this spiritual progress, the writer also gains the merit of serving God in humanity (Jan-Janardan). Therefore, the value for the Guru is directly tied to the spiritual upliftment and fulfillment of the devotees.