I think one of the hallmarks of any truly revolutionary technology is the ease and speed with which it spreads, becomes assimilated, and soon seems 'obvious' to those who were born after its adoption. The wheel being the archetypal example.
I'm no expert on printing presses, but the Wikipedia page on Moveable Type has some good material, including the suggestion that Gutenberg's most important innovation was a greatly improved method for casting letters. I find the elegance of this quite inspiring -- that Gutenberg did not invent 'the printing press' out of thin air but rather made this seemingly minor, but in fact absolutely crucial improvement that almost immediately propelled it from a niche technology into a cornerstone of intellectual life. There are many contemporary parallels...
(Incidentally, printing's rapid adoption was surely in part due to its usefulness not just for intellectuals, but also for the ever-present propaganda efforts of government officials.)