I agree with you that the Internet catalyzed or speeded up English adoption. But note that English has been "the" world language only since the 70s or so -- when the influences of Anglophone culture spread, but even then there was no need to learn English in communist countries or China and even in India and Africa the "need" was far less when trade with Anglophonia :) was minimal or through middle-men
English as the language of science is also fairly recent as the major discoveries until the Industrial age were written (in Europe at least) in Latin as lingua franca.
Entertainment is also an interesting point -- we Americans tend to over-estimate how spread our culture is -- it's only been recent phenomenon since the 80s and more so since the 90s. When I moved to Poland, most people didn't know some of the staples of 70s and 80s tv-land, so my references were known. However they all knew Friends and surprisingly Alf. in my travels in India, China and the Middle East, this was again the case.