User preferences for an uninterrupted experience are increasingly supported by features such as pop-up blockers in browsers. Users also adapt their behaviors to avoid ads. Mark, a 44-year-old IT manager, immediately scrolls a fixed distance to get a top-of-page banner out of sight.

"I always do that," he says. Why? "Those ads are never anything useful to me," he replies. What if the ad is for a computer product that Mark may need at work? "I already know what I want; if I’m interested in a product, I’ll just go to their website."

Hiding the banner

Mark, the user pictured in this test, immediately hides top-of-page banners because "they are never anything useful to me."

Take away for advertisers: Users like Mark are legion. Precise banner-avoiding scrolling is a good reason for advertisers to consider interlocking top-of-page and skyscraper banners that "talk" to each other; it is also a reason for site publishers to avoid placing content in the same area as ad units.

Next: Making sense of all this