A new Firefox browser plug-in known as Greasemonkey is driving some online advertising observers bananas, because it lets Firefox users arrange ads on Web pages the way the users want them to be, even if it's off the page or buried on the bottom.
"As online media buyers, we should be concerned if our ads are blocked," writes WebAdvantage.net President Hollis Thomases in a column on ClickZ.com May 24. "When a user opens a page with Firefox and the ad-blocking script, the page and the ads are at first fully served. Within seconds, however, the ad-blocking script strips out or relocates the ads. The script identifies the ads by their class attribute, ‘ad.’ Ads assigned a different class attribute or injected with a JavaScript onload event handler survive the script.
"Yet the publisher counts the stripped-out ads as served, even if they couldn't be viewed," she continues. "The development community is working on a method of running these user scripts early in the page-request cycle. This would completely eliminate the ad request and, therefore, the false data. For now, Greasemonkey scripts can lead to over-reporting served ads, however small that percentage may be."
Greasemonkey “lets you to add bits of DHTML (‘user scripts’) to any Web page to change its behavior," according to Mozilla Foundation, the creators of Firefox. "In much the same way that user CSS lets you take control of a Web page's style, user scripts let you easily control any aspect of a Web page's design or interaction."
There is also said to be a newly written code available to block Greasemonkey, as well as some reports of threatened lawsuits against the feature, Thomases said.
"Greasemonkey can wreak havoc with fee-based or registration-only online sites," she writes. "Some scripts allow users to view restricted content without logging in. NYTimes.com and Salon.com have already fallen prey."
