1. Samadhi by book distribution

    One should engage in practical service to the Lord. In our Krsna consciousness movement all our activities are concentrated upon distributing Krsna literature. This is very important. One may approach any person and induce him to read Krsna literature so that in the future he may also become a devotee. Such activities will always remind the devotees of the Lord’s lotus feet. By fully concentrating on distributing books for Krsna, one is fully absorbed in Krsna. This is samadhi.

    Srila Prabhupada Srimad-Bhagavatam 10.2.37 purport