Next time you're with a bunch of frequent Internet users, try this survey.

First, request a show of hands from those who like pop-ups -- those little advertising windows that suddenly open over whatever their viewing on the Web. Count on it: You won't see a single palm in the air.

Next, ask how many people have purchased anything in response to a pop-up. Chances are nobody has -- or if they have, they won't admit it.

Finally, expand that last question to include taking any action in response to a pop-up: participating in a poll, entering a contest, subscribing to an e-mail newsletter, accepting a last-minute free-shipping offer on a retailer's site. In an honest group, nearly every hand will go up, however sheepishly.

This decidedly unscientific survey will illustrate an on-line marketing secret: Against all odds, if done properly, pop-ups actually work. Sometimes.

That's surprising, considering that many people profess to despise pop-ups and their cousins, pop-unders (which hide under web pages until users close them), as much as they hate telemarketers. They've been denounced on web sites and in petition drives. They've spawned a whole industry of products with names like Pop-Up Stopper Pro, PopUpCop, STOPZilla, and iHatePopups.

And pop-up ads have forced major Internet players to address their use. AOL and Google no longer allow pop-up ads on their sites. Those two companies, as well as Internet service provider Earthlink, also offer pop-up blockers to their users. Meanwhile, Microsoft Corp. announced plans to include an anti-pop-up tool in an Internet Explorer upgrade in 2004.

Pop-ups aren't even all that popular with advertisers: They account for just 3.5 % of all on-line impressions, according to a report released earlier this year by Nielsen//NetRatings Inc. No wonder the Milpitas, Calif.-based research firm dubbed pop-ups "the black sheep of the online advertising flock."

Finally, to date, there's no definitive research gauging the format's effectiveness, according to experts at the Wharton School at the University of Pennsylvania and elsewhere [See resources, below.]

So why would anybody ever bother with them? For the same reason publishers stick subscription cards in magazines and retailers stuff glossy inserts into Sunday newspapers: Sometimes they actually succeed.

"Pop-ups and pop-unders are getting the consumer's attention, which is the first rule in advertising," says Ron Ossip, senior vice president of marketing for 411web Interactive, an online ad agency based in Los Angeles. "They work relatively well. You may hate them -- but you pay attention to them."

But doesn't that plethora of pop-up-killing products prevent consumers from ever seeing the ads in the first place? Another little secret: Many users disable their blocking software after realizing it may also suppress information they actually want. For instance, I abandoned one tool that indeed stopped pop-ups but also interfered with my eBay auctions and my remote e-mail service.

In addition, pop-ups are comparatively cheap, making them an increasingly tempting alternative for small and midsized companies. Costs vary widely depending on numerous factors, but 35 cents per click is a reasonable average, says Heidi Browning, media director for Organic Inc., a San Francisco-based web development and marketing agency.

Ultimately, entrepreneurs interested in adding pop-ups to their marketing mix must decide whether they're likely to alienate more people than they attract. "The technology is effective," Ossip insists. "It just has to be used in a way that makes sales while respecting the customers.

Following are some tips for smart use of pop-ups on your website:

Set limits: Restrict the number of ads individual users see. Three per session or per day is reasonable. More than five is accelerating toward aggravation.

Avoid reruns: Generally, users should view each ad just once per session. If it constantly reappears, it quickly becomes an annoyance.

Prevent pile-ups: Don't let pop-unders stack up beneath users' browsers so that they have to close a dozen or more after they've left your site.

Schedule carefully: Time ads to appear at intervals throughout the session, just as commercials appear at different points in a television program.

Make it easy: Avoid designs that force users to click repeatedly to close a pop-up window.

Give something away: Consumers may look more kindly on pop-ups that do more than clutter their screens. Offer a gift, a discount, a contest, or a chance to provide feedback.

Keep it relevant: Ads should relate directly to pages being viewed. On a florist's site, for instance, a buyer considering a particular bouquet might see a pop-up offering a price break on the next size up.

Surprisingly, pop-ups and pop-unders may prove most effective just as users leave a site. "Exit pops" can be used to entice visitors back with promises of free shipping or last-minute discounts, in much the same way a car salesperson suddenly sweetens an offer to keep a potential buyer from walking out of the showroom.

One of Ossip's clients, a mortgage company, uses an exit pop encouraging visitors to return and spend a few minutes providing preliminary information. Anywhere from 3% to 10% of departing visitors return; of those, 5% to 10% apply for financing or take other action, he says.

The approach "makes sense because it's not intrusive," Ossip says. "You're using it for a client who has already visited your site and shown interest."

But he warns that once visitors become paying customers, companies should stop the pops. "You've already made the sale," Ossip says. "So why annoy them?"

"Are Pop-Up Advertisements on the Web Illegal?"
Article by Douglas M. Isenberg, founder, editor and publisher of

"Darn Those Pop-Up Ads: They're Maddening, But Do They Work?"
Article from Knowledge@Wharton series prepared by The Wharton School at the University of Pennsylvania.

Pop-up ad policies at AOL, and Google.

"The State of Online Advertising"
Comprehensive 2003 report by Nielsen//NetRatings Inc.