Source: Srimad Bhagavatham : Its Message for the Modern Man by Swami Shantananda Puri Maharaj
Srimad Bhagavatham (11:20:17)
नृ-देहम् आद्यं सु-लभं सु-दुर्लभं
प्लवं सु-कल्पं गुरु-कर्ण-धारम्
पुमान् भवाब्धिं न तरेत् स आत्म-हा
"All Sadhanas are possible only when we are endowed with a human body. This body of ours is the most efficient boat. Make the Guru the oarsman who will guide the boat and take it across the ocean. The Lord's Grace is the favourable wind in which the boat can sail swiftly and you can easily cross the ocean of Samsara (phenomenal world). Not to make use of the body in this manner is equivalent to committing suicide.''
Please check these: Excerpts from a discourse by our Sri Sri Muralidhara Swamiji
To collect people living around one's home and help them chant the Lord's Name is verily service to the Guru. Or to follow the special instruction given to him/her by the Guru is verily 'service' to the Guru.