– John Wanamaker
If we're going to sling arrows at online advertising, I think we have to start with the fact that there are a lot more publishers than there were back in the day, and virtually all of them have an undifferentiated audience of "eyeballs". It's still possible to get high CPM rates, as long as you've got a targeted audience and a sales team.
[citation needed]
A famous quotation about the effectiveness of advertising, by a business person "considered by some to be the father of modern advertising."
http://en.wikipedia.org/wiki/John_Wanamaker
"Half the money I spend on advertising is wasted; the trouble is I don't know which half."
I'm making the assumption that Coke and Nike, et al. are smart enough to have at least rudimentary knowledge of the effectiveness of their brand advertising. Is this an assumption? Yes. Is it a more reasonable assumption, a priori, than the alternative? I think so.