From Internet Outsider
Internet-sleaze detective Ben Edelman has published a new study showing that "forced visits" triggered by unwanted pop-up ads may significantly increase reported traffic statistics at many sites. Because traffic statistics are important for business and investment decisions, this artificial traffic may be helping some companies win business/investors at the expense of others. To anyone who has ever had his or her screen littered with unwanted pop-up ads, the practice is obviously sleazy. At public companies that report traffic statistics, it might even be construed as securities fraud.
A "forced visit" occurs when a pop-over or pop-under for a third-party site automatically launches when you are visiting an unrelated site. As Edelman shows, such ads can eventually count as a "visit" to the advertiser’s site, even if your only interaction with the pop-up is to delete it. Using screen shots, Edelman details how such ads produce traffic for even big companies like Orbitz (Away.com) and Bolt.com. Edelman estimates that, at sites that use such tactics, "forced visits" could account for a third to a half of all traffic.
This practice presumably does not affect traffic numbers at sites that don’t use pop-up ads, such as Yahoo and Google (so it doesn’t explain the ongoing discrepancy between site-reported traffic stats and Nielsen/Comscore traffic stats). It probably does inflate such companies’ advertising revenue, though: Sites that buy pop-ups/traffic need somewhere to find future "visitors."
Given the recent regulatory focus on spyware and inflated newspaper subscription numbers, it is reasonable to assume that regulators will eventually focus on such "forced visits." As Edelman suggests, in the wake of YouTube and other high-profile emerging-company acquisitions, Internet companies have an incentive to pump up traffic statistics. The smart ones will carefully weigh this incentive with the threat of future fraud charges, hellish publicity, and fines.