Christian Chabot, in his TC 2014 keynote, likened Tableau to digital photography vs traditional business data analysis' film.
It's an excellent metaphor, capturing the essence of how Tableau transforms the nature of the relationship between people and the data that matters to them.
I'm glad I was able to help.
The original post, March 19, 2013
Linked in "Best of the Tableau Web...", March 27, 2013
Echoed by Tom Brown, The Information Lab,Oct 28, 2013