Those Annoying Pop-Under Ads (And How to Stop Them)

They came out of the blue. One, then another, suddenly a swarm. Like aggressive flies assaulting the comfort of a summer evening. Here come the pop-under ads, the latest electronic pests of the Internet.

(click thumbnail)They came out of the blue. One, then another, suddenly a swarm. Like aggressive flies assaulting the comfort of a summer evening. Here come the pop-under ads, the latest electronic pests of the Internet.

Annoyance over these stealth Web pages has quickly become a favorite topic of Netizens. In fact, here in New York City, disdain for pop-unders is beginning to steal thunder from obnoxious cellphone users and those shrill prerecorded seat-belt warnings in taxi cabs.

Just as we're asking "Can they legally do this?" comes the awful news that these pushy ads might actually work. Jupiter Media Metrix, the research firm, recently reported that one of the most egregious purveyors of pop-under ads –, a consumer electronics retailer – is now the fourth most visited Web site on the Internet (just behind AOL, Microsoft and Yahoo).

Pop-unders, for those who don't know yet, are advertisements that – without your permission – plant themselves under Web pages on your computer screen. A variation of the obnoxious pop-up pitches made famous by America Online, this new breed of ad quietly lurks in the background until you stumble into it after closing the foreground pages.

Thankfully, some degree of comeuppance may be in store for the aggressive marketers who are using this new guerrilla technique. Although Jupiter Media Metrix found that pop-under ad campaigns generate mass reach online, they apparently fail to convert browsers to buyers.

The data shows that although reached 32.8 percent of the Web's entire audience between January 2001 and May 2001, the company also experienced a large traffic drop-off, with 73 percent of unique visitors leaving the site or window in less than 20 seconds.

"Looking only at reach, it would appear that has deployed an incredibly successful campaign," said Marissa Gluck, senior analyst at Jupiter Media Metrix. "However, consumer behavior tells a different story. As advertisers become increasingly intrusive online, consumers react just as they do with their TV remote control – they eliminate advertising they don't find relevant or entertaining. That's what's happening with"


The ads have made a household name of X10 Wireless Technology Inc., based in Seattle, Wash. The company did not respond to our request for an interview. However, since so many Web users end up at X10's site, the company posted a FAQ page devoted to explaining its use of the controversial pop-under technology (

"You may have recently seen an advertisement appear on your computer while surfing the Internet. These ads are unique in that they appear as a new window. They are 100 percent safe and 100 percent legal," the company contends.

X10, however, makes no claims that the ads aren't 100 percent annoying. "As the Internet is growing and evolving very quickly so are the ways and means of advertising online. A few years ago, the standard 468 x 60 'rectangle' ads at the top of Web sites were very new. Many people were uncomfortable with these ads but with time, people got used to the ads," X10 tells visitors.

"In the last year many different sizes and styles of ads have been used to try to add more value to the advertiser. is simply using a new form of advertising. Please try to understand that this type of advertising is what keeps the Internet enjoyable as it pays for operational costs behind the sites you enjoy visiting for free. There are some content-based sites that do not accept advertising, yet charge a subscription fee to view their content. This tradeoff is the current environment of the Internet today."

Once again, X10 uses the familiar argument that if the Internet is to remain "free," advertising must remain unfettered. It's the same pitch made last year by Kevin O'Connor, chairman and CEO of DoubleClick, in response to the outcry over his company's well-publicized dossier-building activities on Internet users.

O'Connor went so far as to argue that advertising targeted to the "preferences and habits of consumers" is essential. Without these personalized ads, and the subsequent loss of privacy required to deliver them, he claimed, "Web sites will have to begin charging consumers" for access.

These arguments are designed to invoke fear. However, they ignore the history and original promise of the Internet. It was public funding, not advertising, that originally built the network. It was created, not as a medium of commerce, but as a public resource for interactive communications. It was the Internet's noncommercial attributes that made it a success. Only after it was built and already immensely popular, did the commercialization rush begin.


Now, as a spate of ill-conceived Web ventures are failing, some Internet entrepreneurs, in desperation, have turned to pop-unders, an ad technology originally conceived by the online pornography industry. The law may allow it, but the good news is that Web users can fight back.

The key to blocking most pop-under (and "up") ads, it appears, is to disable JavaScript on your Web browser. Doing this universally, however, prevents certain types of sites – such as online banking – from performing properly. The trick is to disable JavaScript selectively on a site-by-site basis. It was David Lerner, proprietor of Tekserve, the New York City Apple Computer specialist, that helped me find a realistic solution to block the ads when he passed on this URL: In it, I found an answer that can reduce the ad plague for both Mac and Windows users.

In a nutshell, using browser preferences creates a "security zone" around offending sites. Within this zone, you can selectively disable JavaScript for the specific sites whose ads you wish to block. On Internet Explorer 5.0 for Macintosh, I went to "Preferences," selected "Security Zones," and then selected "Restricted Sites Zone." I then entered the custom settings panel and disabled scripting, plug-ins and Active X controls. Then I selected "Add Sites" and listed the URLs of those sites that send me the ads.

Bingo, it worked. This virtual flyswatter zapped the pests dead!