>> Sales are not the target of SEO......traffic and visibility is.
If I could just expand on this a bit. :)
...... targeted traffic and targeted visibility is.
Proper SEO, and proper site message/navigation/professionalism go together.
So if Jim's Apple Farm has SEO done, and gets a ton of traffic, but from people looking for Apple computers, rather than apples to eat, it doesn't matter what his site message is.
Just as if Jim gets the targetted traffic, it's up to the site to sell/convert the user. You can't have one without the other.
As far as banner advertising, I think another big problem is the medium's lack of ability to change and adapt with the times. For example, as sean pointed out some time ago, 468x60 is still the average, predominant banner size. This size was justified when we were (almost) all running 640x480. Look how much screen size that used to take up, compared to today. These banners are tuned out by everyone nowadays. Cnet's ads still catch my attention, as do most skyscrapers. But look at the small representation of the new IAB banner sizes web-wide. Not many are taking advantage of this.
Compare that to SEO, we have to stay on top of everything daily. We know when algos change, when databases update, when SERPS look different, when PPC listings are added - the list goes on. SEOs constantly evolve with the times to stay on top of the game.
If advertising companies, especially bannerbrokers, tried as hard to stay ahead of the curve with targeting, demographics, rich media, and different ad sizes, I think they (and subsequently we) would be in much better shape.