"Tens of thousands of junk Web pages, created only to lure search-engine users to advertisements, are proliferating like billboards strung along freeways. Now Microsoft researchers say they have traced the companies and techniques behind them. A technical paper published by the researchers says the links promoting such pages are generated by a small group of shadowy operators apparently with the acquiescence of some major advertisers, Web page hosts and advertising syndicators."

[cs.ucdavis.edu...]

. . .

"The Microsoft research findings . . . determined that much of the spam ad traffic was being funneled through the Internet addresses of just two Web-hosting companies. Phillip Rosenthal, chief technology officer of one of the companies, ISPrime, an Internet services company based in New York, said the activity had been traced to a single customer and violated the company’s acceptable-use policy. He said the company’s relationship with the customer, whom he would not identify, had been severed after the company was notified about the Microsoft paper by a reporter."