Paidcontent reports on a study conducted by MarketingSherpa on advertising bechmarks, which showed the effect of online ad placement in relation to the fold.

According to the report, most individuals don‘t see most ads served to them—especially ads served below the fold. Despite this result, media delivery reports rarely include information on whether, or what percentage of, a media buy was served above or below the fold. On the chart below, the bottom of the blue area represents the percent of total viewers who see an ad; the top represents the percent of total viewers who scroll to a point where the ad is visible on their screen. Clearly, just being above the fold makes a huge difference.