As Consumers Revolt, a Rush to Block Pop-Up Online Ads

"AdvertisementBanners.com, which places pop-under ads on Web sites, has found that 20 percent to 25 percent of Web users have pop-up blocking enabled on their computers, double the rate of a year ago, said Chris Vanderhook, the company's chief operating officer. Some advertising companies say that a smaller percentage of people are using blockers, but there is agreement that use of pop-up blocking is increasing."