D Squared, based in San Diego, sells software that helps people block pop-up advertisements while they're surfing the Web. To promote the software, the company to deliver ads as often as every 10 minutes to some PC users. The Windows feature (not to be confused with Microsoft's instant-messaging service) is designed to let network administrators notify users about critical maintenance--for example, when servers are about to go down.
The Federal Trade Commission sued D Squared in federal court in Maryland, and last month won a preliminary injunction preventing it from sending the ads. D Squared , effectively overturning the injunction Monday in a hearing before U.S. District Judge Andre M. Davis, according to an online federal database that tracks court proceedings.
The decision means D Squared can resume sending ads through the notification system pending a trial on the matter, scheduled for early next year. It was unclear what impact the ruling would have on end users, however, as the issue has already led Microsoft and others to take steps to prevent the Messenger feature from being used this way.
Microsoft recently to the Windows Messenger, and AOL has made to its Internet service to stop the flaw from affecting its subscribers.
Pop-up advertising is considered to be among the most effective formats for online advertisers, scoring higher response rates than banner ads. But Web surfers also consider pop-ups among the most annoying online marketing techniques.
A growing backlash against pop-ups could make the format less popular among ad buyers, as software makers and Internet service providers increasingly add pop-up blocking features to Web browsers and plug-ins. Microsoft next year plans to add a pop-up blocker to its all-but-omnipresent Internet Explorer browser, .