How does the creation and study of a Guru's biography, like the Shri Sai Satcharita, create a cycle of service and merit?

The preface discussed in Chapter 0 explains a profound cycle of service and merit. Firstly, the Sadguru takes service from a devotee who writes a detailed biography. Secondly, when other devotees study and perform Parayans of that work, the writer is credited with the merit of serving 'God in humanity' (Jan-Janardan) and performing public service. In turn, those devotees who study the work are able to achieve the purpose of their lives. This establishes a spiritual ecosystem where the Sadguru accepts service from both the author and the readers, creating a powerful bond within the community of devotees and with the Guru.