Conversation so far:
When did A. C. Bhaktivedanta Swami Prabhupada's religious journey start?
In 1922, when A. C. Bhaktivedanta Swami Prabhupada first met his spiritual master, Bhaktisiddhanta Sarasvati Thakura, he was requested to spread the message of Chaitanya Mahaprabhu in the English language
Did A. C. Bhaktivedanta Swami Prabhupada do anything else with Bhaktisiddhanta Sarasvati Thakura?
In 1944, from Bhaktisiddhanta Sarasvati Thakura's front room at Sita Kanta Banerjee, Calcutta, A. C. Bhaktivedanta Swami Prabhupada started the publication called Back to Godhead,
Did A. C. Bhaktivedanta Swami Prabhupada have a following?
A. C. Bhaktivedanta Swami Prabhupada's early disciples called him Swamiji. He became well known as Prabhupāda and his disciples called him by this name from late 1967 early 1968 onwards.
Was A. C. Bhaktivedanta Swami Prabhupada recognized for anything else besides being Swamiji?
In 1947, the Gaudiya Vaishnava Society recognised A. C. Bhaktivedanta Swami Prabhupada's scholarship with the title Bhaktivedanta
Did A. C. Bhaktivedanta Swami Prabhupada write anything else besides Back to Godhead?
In 1950, A. C. Bhaktivedanta Swami Prabhupada began his commentary and translation work of the Sanskrit work Bhagavata Purana.
Were A. C. Bhaktivedanta Swami Prabhupada's writings famous?
In February 2014, ISKCON's news agency reported to have reached a milestone of distributing over half a billion books authored by A. C. Bhaktivedanta Swami Prabhupada, since 1965.
When was the text Back to Godhead written?
In 1944, A. C. Bhaktivedanta Swami Prabhupada started the publication called Back to Godhead, for which he acted as writer, designer, publisher, editor, copy editor and distributor.
Is there anything else interesting about the A. C. Bhaktivedanta Swami Prabhupada article besides meeting Bhaktisiddhanta Sarasvati Thakura, making Back to Godhead, and having over half a billion books distributed?
A. C. Bhaktivedanta Swami Prabhupada's guru, Bhaktisiddhanta, had always encouraged him to print books.

Question: What that it mean?
Self-contained rewrite: What did A. C. Bhaktivedanta Swami Prabhupada's guru, Bhaktisiddhanta mean by encouraging him to print books?