A look at a spyware company

This explains the vitriol aimed at Direct Revenue. The company, located in a loft above a clothing boutique in New York's hip SoHo district, has been a pioneer in a seamy corner of the booming Net advertising industry. Although it is small by some corporate standards, having generated sales of about $100 million since its start in 2002, its programs have burrowed into nearly 100 million computers and produced billions of pop-up ads.

Direct Revenue's swift rise illustrates the intertwining of spyware and mainstream online marketing. The Web is the hottest game in advertising, but what's rarely acknowledged is the extent to which unsavory pop-ups boost the returns. Here's how it often works: Sellers of advertising, ranging from giant Yahoo! Inc. to much smaller networks, recruit clients, tally the clicks their ads generate, and charge accordingly. But then Yahoo and the other advertising companies sign up partners that distribute the ads beyond their own sites in return for a fee, and those partners sign up other partners. Down the line, a big piece of the business winds up in the hands of outfits like Direct Revenue, which disseminate the ads as pop-ups and share revenue with their more mainstream partners.