Srila Prabhupada on book distribution

Srimad-Bhagavatam 10.2.37
The word kriyasu, meaning "by manual labor" or "by work," is important in this verse. One should engage in practical service to the Lord.

In our Krishna consciousness movement all our activities are concentrated upon distributing Krishna literature. This is very important. One may approach any person and induce him to read Krishna literature so that in the future he may also become a devotee.

Such activities are recommended in this verse…. Such activities will always remind the devotees of the Lord's lotus feet. By fully concentrating on distributing books for Krishna, one is fully absorbed in Krishna. This is samadhi.