Here is a link to a great video that really drives home the point about digital media for anyone who may have doubts.

Do you think, as it suggests, that words on paper will seem as strange to our grandchildren as milk delivery does to us?

I particularly like the statement that in 1910, mass media spread news faster than word of mouth and that now word of mouth spreads news faster than (traditional) mass media.  If what's old is new again, I've often thought of social media as word of mouth/gossip on steroids.

http://www.youtube.com/watch?v=sM-kGGURWCE