Sree Sree Guru Gaurangau Jayatah!
Prachar (preaching) is not for prachar's sake, it is not for mundane temporary benefits. It will be wise to perform all forms of bhajana (devotional practice), including Kirtana, for the propitiation of Sri Krishna and His devotees. Wherever we may go or stay by the Will of Supreme Lord Sri Krishna, Who is All-Good, we should perform bhajana, we should not forget the devotional purpose of our life. Everything will remain in this world; nothing will go with us, only devotion to Sri Krishna will go with us. So, it will be unwise to sacrifice eternal benefit for the sake of mundane temporary benefits. The greatest hurdle of Krishna bhakti is committal of offence at the Lotus Feet of Vaishnavas. We should always remember the teachings of Lord Sri Chaitanya Mahaprabhu.
Chanting of the Glories of Sri Krishna — His Name Form, Attributes and Pastimes is the best form of Bhakti. While performing Bhakti (Kirtana Bhakti), prachar will be automatic. There is no need of making separate endeavour for this.
--- Jagad-guru His Divine Grace Srila Bhakti Ballabh Tirtha Goswami Maharaj