AndyA - 12:52 pm on May 14, 2010 (gmt 0)
I agree with Lame_Wolf. Ads placed at the bottom of the page, after an article, often are more user friendly than ads placed at the top or near the middle of the page. Who wants to immediately click on an ad right after the page loads?
Obviously, they arrived there to do something. Read an article, perhaps. So they're going to change their mind because of an incredibly wonderful offer presented to them from an advertisement at the top of the page? Not likely.
What seems more likely is that they will read the article, or view the image or whatever they came to that page for in the first place, then will be looking for other options, either another page on the site, or perhaps an advertisement conveniently located at the end of the article.
I try to consider how people use a site, not what advertisers think is best, and of course what works for one site might not work for another, but I can't remember the last time I scrolled back to the top to click on an ad, or clicked an ad immediately after arriving at a page.