"It's critical that there's consistency in how impressions are counted on pages using AJAX," said Sheryl Draizen, senior vice president and general manager of the IAB.

"We're giving confidence to the numbers," added Draizen, referring to the ad impressions that determine how much money advertisers pay publishers for placed ads.

The guidelines are geared to online browser or browser-equivalent-based Web activity, which no longer links page content changes to ad serving.

Ajax and JSON technologies have grown increasingly popular by providing updated content to Web users without forcing users to refresh an entire Web page. While improving the user experience, however, Ajax and JSON make traditional metrics such as page views and ad impressions less relevant and more difficult to gauge.

The IAB officially unveiled its Rich Internet Application Ad Measurement Guidelines at an IAB Leadership Forum in May. The agency has since called on agencies, publishers and tech vendors to review the guidelines, and to offer ideas and criticisms for public debate.

On Wednesday, the industry offered its support for the guidelines. "These guidelines have been reviewed and endorsed by the AAAA's Digital Marketing Committee," said Mike Donahue, executive vice president of the American Association of Advertising Agencies.

The guidelines state that "in instances where significant user activity (click-through and responding to mail and changing search options through clicking or typing, etc.) is present, this activity can be directly tied to ad-serving and counting provided that counting rules are defined in a consistent and fully disclosed manner."

The guidelines go on to acknowledge that "in special circumstances, due to the nature of the application, there may be no material user activity, for example, a single streaming event (e.g., financial tickers, sports game coverage, long single-stream video content). In these cases, disclosure and counting must abide by the auto-refresh guidelines of the current IAB Ad Impression Measurement Guidelines."

An issue the IAB has yet to conquer is the proper measurement of audience page-views in an increasingly AJAX-heavy Web universe.

This looming problem led Nielsen//NetRatings back in July to announce that it will no longer issue rankings based on page-views. Instead, NetRatings said it will be adding new measurements, including total time spent on a site and total visits, to provide what it believes will be a more comprehensive snapshot of how much visitors are using a given Web site.

"We have a group working on better audience measurement standards," said the IAB's Draizen. "Right now, we're happy to have brought resolution to the issue of measuring ad impressions."

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