There's no way this banner did anything in reality. Corporations didn't upgrade because of their tooling, not youtube. What corporation upgraded to make sure their employees could youtube harder?
Ultimately, I think top-down change at enterprises is much faster than bottom up, and a national news story is just the sort of thing to spur a lot of top-down changes.
Don't underestimate the power of employees to influence employers.
iPhones didn't end up all over the enterprise space because Blackberry walked away from the market.
My guess from my time in the trenches is about 1 in 5.
http://gs.statcounter.com/browser-version-partially-combined...