Intrusive ads cause 11% drop in traffic

Jakob Nielsen's Alertbox for March 26
> http://www.useit.com/alertbox/annoyances.html

INTRUSIVE ADS CAUSE 11% DROP IN TRAFFIC

People who used a site stripped of ads reported that they were 11% more likely to return or recommend the site to others than people who were exposed to the same site with ads.

The drop in expected future use was even greater in the test condition where the site used pop-ups or pop-unders.

These findings come from a study by Scott McCoy (College of William and Mary) and colleagues, published in the March issue of the Communications of the ACM. Full paper at:
> http://tinyurl.com/ynrp3l

Here's the conclusions for that study >

Our findings suggest that advertisements do have significant effects on retention of the site. Also, advertising content that is non-congruent with the site's content seems to lead to greater effort in reconciling the differing content, and ultimately greater memory of both the Web site and the advertisement.

Intrusiveness is also important for both Web site designers and advertisers. Pop-ups and pop-unders seem to be more intrusive than in-line ads, implying that users should not be interrupted from their online tasks to close the extraneous windows.

This article is a first step toward a deeper understanding of Web advertising, providing a controlled study to isolate a variety of factors and outcomes. Such understanding would enable researchers to design future studies using different ad types and different locations on the page. Designers should realize the magnitude of ill effects caused by advertising. Although some of the differences were not large in magnitude, reducing the likelihood of a person's return by 11% might be a cost that is too great for a site host to bear. Discovering that pop-up and in-line ads differ greatly in measures of intrusiveness, a host might play it safe and make use of in-line ads. As theory and practice begin to converge in this area, perhaps what has been described so often as a wild new frontier might finally take a few steps toward being tamed.

This is self-reported data, so it's not necessarily true that the loss of usage from intrusive ads is exactly 11%. However, there is no doubt that such design elements are annoying and that annoyances *will* cause users to turn to other sites.

For data on *how* annoying different kinds of ads are, see:
> http://www.useit.com/alertbox/20041206.html