could be the subject line for this study quoted in Micro Persuasion stating that One Billion Dollars in Internet Advertising is Wasted by display ads visible to about 70% of web users but only seen by about 25% because the ads are displayed "below the fold" requiring people to scroll down a web page.
This doesn't surprise me as these ads, like the original banners, are no different from interruption advertising in print or on TV without the relevancy of search ads. This tired approach is no longer effective in any media. We live in an age of permission based marketing and if the web is used as an interruption tool advertisers can't really expect better results.
It's one more indicator that web based marketing has become more complex and to be effective needs to consider the effect of social media and networking on the buying behavior of today's audience. As this chart here shows, the growth in online advertising over the next five years will be considerable but to be effective it has to take advantage of what the web has to offer to increase effectiveness.
Just to slap more ads including rich media ads won't bring the necessary ROI unless they are relevant to the content and compelling.
This is a key message traditional marketers need to understand as they shift more of their marketing budgets to the web.