• by Tameka Kee , June 12, 2007

An Atlas Institute study has found that almost 67% of Web ad conversions (sales confirmations, requests for information, or other advertiser-defined actions) came from users who saw ads across multiple sites.

While such "overlap" might seem like common sense, analysts at Atlas Solutions -- the research and technology arm of aQuantive -- said that online advertisers are only beginning to quantify the cumulative effects of user exposure to ads across multiple sites.

"Media planners and buyers have been looking at their campaigns in terms of how many conversions they get from each specific site," said Young Song, vice president of analytics, Atlas.* "But there are sites that are delivering a ton of value to a media plan that ultimately gets lost through such a siloed analysis."

Attributing the full value of a user conversion to the last site visited (or the last click) is the standard industry practice, but the Atlas research highlights emerging campaign measurement capabilities that media agencies can use to create cost-effective, comprehensive digital media plans.

One example of such technology is a tool that allows advertisers to "see all the ads that have been delivered to a user in 90 days, look at the different touchpoints, and allocate the conversion attributes effectively based on that information," said Song.

A holistic view of impressions is built into the performance metrics of off-line advertising, and as more traditional media dollars and decision-makers move online, "it's going to force the issue," said Song. "They're going to question the rules and the validity of a specific budget tied to high-priced CPMs, for example."

While examining a user's entire online experience with a campaign--from rich media and Web video to search patterns, and ultimately, a conversion--can help advertisers more effectively plan campaigns, the practice could also raise concerns about behavior tracking and privacy.

According to Song, "conversion attribution is about taking that data that already exists and going upstream with it." By using fundamentally anonymous data such as cookies and date and time stamps from ad-servers, media agencies can increase the ROI of any given media plan and move beyond the last click.

* This article was modified after its original posting.