'Invisible Ads' Scam a Real Issue, But Damage May Be Slight

Online advertisers may be getting cheated out of ad impressions on some ad networks and ad exchanges, according to research from Ben Edelman, assistant professor at the Harvard Business School and an expert on spyware and online advertising fraud.

In his latest research, Edelman documents how a number of publisher sites are causing dozens of ads to load in hidden browser windows, sometimes as many as 90 at a time. The ads register as impressions to the ad networks and advertisers, but are never seen by users.

“This has become the business model for some publishers,” Edelman told ClickZ. “I’ve worked with advertisers that have saved thousands of dollars when this kind of activity is found and eliminated. I think that’s pretty significant.”

But Eliot Kent-Uritam, associate media director for MediaSmith, does not see this particular issue as a major problem for advertisers.

“It’s a pretty specific issue involving some minor sites. Some of the networks themselves are major, but it would be a different story if this were happening with some big-name sites,” Kent-Uritam told ClickZ. “Any time you deal with an ad network, there are going to be issues about where your ad appears. That’s why it’s important to know what you’re buying, and keep track of your performance.”

Edelman has found examples of this kind of abuse by publishers on several different ad networks, he said. One case involves the now-defunct site MyToursInfo.com. During Edelman’s research in January 2009, which he first shared with the Wall Street Journal, he found that a single visit to that site resulted in 31 invisible iframes, each with three ads on a page. Among those 90-plus ad impressions were ads served by Burst Media, ValueClick, Adtegrity, MediaShakers and MediaWhiz’s Adnet, among others.

Edelman cited several examples of this happening when an ad exchange or ad optimization tool was involved. In the MyToursInfo.com example, he found ads that were brokered through exchanges like Yahoo’s Right Media or ContextWeb’s ADSDAQ, as well those using ad optimization tools from Zedo or the Rubicon Project.

In another example from January, a visit to RouteTraffic.com initiated 37 invisible iframes, with ads from several ad exchanges and networks. In that example, other publisher sites were also involved, either as accomplices looking to artificially inflate traffic or ad impressions on their own sites, or as victims of third parties selling ad space at rock-bottom prices, Edelman said.

The technique they are using involves launching new pages in iframes when a visitor comes to a page. These iframes will be created with a height and width of 0 pixels, so a user will never see the ads. Some examples get very convoluted, launching several levels of nested iframes, Edelman said.

While the implementation can be complicated, it should be easy for ad networks and other providers to spot and eliminate, according to Edelman. The problem, he said, is that ad networks’ incentive to stop the practice is skewed.

“The networks are making money from every ad placement, even if the ads don’t perform. It won’t be good for them long-term, if they get the reputation for being no good, but in the short-term, they’re making money,” Edelman said.

Edelman and MediaSmith’s Kent-Uritam both agree that asking questions up front and tracking performance after a campaign launches are two important safeguards an advertiser can take when buying ads from an ad network.

Some clients, particularly those running direct-response campaigns, are more willing to put up with a certain level of “shenanigans,” as Kent-Uritam puts it. As long as the performance of the overall campaign fits their direct-response goals, the client will not worry about losing some of its spend to non-performing ads, he said.

Other clients, especially bigger brands, demand to know everywhere their ads might show up, and will not accept any level of uncertainty, he said. “For these advertisers, something like this issue would only affect them if it were happening on tier-one or tier-two sites.”

“Advertisers should be asking lots of questions,” Edelman said. “What sites will my ad be shown on? How will anyone verify that the landing pages are not invisible? If someone gets caught doing it, who loses — the advertiser or the network? These are fair questions that should all be clarified up front.”