There are plenty of myths that have far outlasted the data that showed them to be wrong. "The Earth is flat", "Heavy objects fall faster than light ones" and Noah's Ark all come to mind. The most expensive myth around today, though, could be the $220 Billion (with a "b") spent on unmeasured advertising every year.
Check out mlife for a rare post-dotcom-crash example of big spending for a web launch. Here in New York you'll see them on taxi tops, posters, big ads, the whole nine yards. Visit the site and it won't even say what they do until they launch next week. Go figure.
Randall Rothenberg is almost always right, and he's correct again in the start of this column. Entire media companies are about to bite the dust because advertisers are just now (fifty years later) realizing that almost all ad money is wasted... but now, they can tell which part works.
Myths make people emotional, of course, and there's bound to be plenty of angst before this argument is settled. I mean, I just bought a lot of ads for my new book, but I did it with my eyes opened and my accountant's eyes clearly focused on the results we generated. I don't think direct advertising is in any danger of going away...(like it or not, spam appears to be here for a while too), but I just don't get the whole Super Bowl commercial thing.