Mr. Spock gets one of Srila Prabhupada’s books to read while in a mission in the starship Enterprise :-)
Srila Prabhupada: The real preaching is selling books. You should know the tactic how to sell without irritating. What your lecture will do for three minutes, but if he reads one page his life may be turned. Letter to Bali-mardan, September 30, 1072.