Why do Lubavitcher חסידים print “ספר של בינונים" in many different places — something about outward expansion of wellsprings?
There's a famous story that the Baal Shem Tov encountered Moshiach and asked him when he would finally come -- "when your wellsprings of Torah are spread out there." So I would see this as trying to fulfill that mission.
A recent Israeli postage stamp commemorated 200 years since the death of Rabbi Shneur Zalman of Liadi, the 1st Lubavitcher Rebbe and author of the Tanya (and the Baal Shem Tov's student's student). Instead of featuring his picture, it has a picture of a Tanya book and a quote about the spreading of the wellsprings.
I've heard about efforts in the past to print one copy of the Tanya in each of the 50 US states, as well as all the countries of the world.
There's also kabbalistic matter about sparks of holiness that have been scattered across the world, that we need to reunite. That's probably related.