"Only 25% of web users see display ads placed 'below the fold'"

"Below the fold" in this context means users have to scroll down on their computer screens to see them.

The figure in the headline is from research by MarketingSherpa, cited by Dan Mitchell in his "What's Online" column in the April 19, 2008 New York Times Business section.

Turns out half of all display ads appear there, which means that about $1 billion annually is "wasted," according to Steve Rubel of micropersuasion.com.

He told Mitchell, "Advertisers are going to eventually wake up and recognize that unless its a highly visible placement, banners get you largely nowhere."

I'm reminded of the remark of department store merchant John Wanamaker, who said, "Half the money I spend on advertising is wasted; the trouble is I don't know which half."