"And yet, given that I am exposed to adverts for about 20 different brands of cars i.e. every single brand available in my locality, surely the net effect is to cancel each other out?"
That's why the shock and awe. They're trying to get the most attention from you so that it sticks in your mind the most. So that out of all those 20-some car makes, theirs is the one that sticks out when you think, "I need a new car."
"It's basically a stupid arms race - if none of them advertised, everyone would still know what brands are available simply by seeing them in the streets, the net effect on sales would be basically zero and each of the car companies has saved a mint. But just because 1 of them is doing it, they all have to do it to keep up??"
Yup, because otherwise one may not know where to start looking. Sure, you say just look on the street. Only thing is, there are lots of streets. Sometimes, product searching becomes like trying to find a (nonferrous) needle in a haystack.
Biting the hand that feeds IT
