The first time I saw the word 'Sour' whether it be in Crips (Potato Chips in your language), or in Bready products was around the mid-90's. In England.. sour was just that... not nice and who wants Sour tasting stuff?
I thought it weird that Sour Cream Crips were all the rage. Now, it's quite normal here, just like Self-Service Checkouts are.., they were in America first of course.
Drive through Drug-Stores never quite caught on.. as did the Self-Service Teller machines, where you card was sucked through pipes.., that always did make me laugh.
Chips (crisps) with sour cream and onion is popular here. Not my favorite, though. Sourdough bread on the other hand I like very much :)
It is here now, but it's another description for 'Cheese and Onion', which still exists.