> Ogilvy found that, on average, headlines placed below an image are read by 10% more people than headlines above. Since reading the headline is a prerequisite of reading the body copy, you’re losing a potential 10% of your audience if you’re distracting them with an image in the wrong place.

Actually, you'd be losing at most about 9% of your audience. I know that's a bit of a nitpick, but it bugs me when people equate "not X% more" with "X% less".

Also, to actually lose 9% of your readers to your headline position, you have to make the very optimistic assumption that you're not losing readers to any other factor.