I always viewed cultural
imperialism more as the outward trappings of one society creeping into another --
Italians wearing
New York Yankees baseball caps, etc.
Per my definition, the classic example of American cultural imperialism gone a bit too far was an event on the first day of my recent trip to the United Kingdom, wandering the street across from Harrods.
As I looked through a tie shop, I suddenly realized that I was looking through an entire rack of Dilbert (a cartoon satirizing U.S. corporate/engineering culture) and Peanuts (perhaps the most American of all cartoons) ties, while the latest R.E.M. single was playing on the store's radio.
It was at that point that I decided London was New York with different money and natives who can't drive (wait a minute, New Yorkers can't drive either). Fortunately, this jetlagged observation turned out to be only partly true, as I found when my group returned to London on the final weekend of our tour.