Publishers Drop Twice as Many Cookies as E-Commerce Sites

BlueKai outpaces comScore, per Truste study

In the online advertising world, the pro-cookie argument may hold that the ubiquitious tracking mechanism ensures a better site experience. But of course, for many Web publishers, the use of cookies has everything to do with monetization.

In a recent study, online privacy firm Truste found that publishers’ homepages average more than twice as many persistent third-party cookies as those of e-commerce sites.  Such third party cookies often allow these pubishers to know things about their visitors, such as whether they might in the market for a new smartphone based on their recent Web activity.

Still, one might think that e-commerce players are more cookie-happy than publishers, given their shopping focus. But Kevin Trilli, vp of product at Truste, theorized that many publishers employ lots of third party cookies from ad tech firms promising better ad targeting.

On the flip side, e-commerce sites generally limit their homepages to their own cookies in order to personalize the site experience, bringing in third-party cookies when a user puts a product in his shopping cart or clicks to buy it because those actions show intent, an especially valuable ad targeting signal.

That publishers’ homepages will host more persistent third-party cookies than e-commerce sites’ isn’t a hard and fast rule. Fox News had 48 persistent third-party cookies whereas had an almost as bountiful 36; eBay had 3 but USA Today wasn’t too far off with only 11, Truste found. For what it’s worth, Adweek had 56, which “considering the subject matter and audience is not surprising,” Trilli said.

The publisher-versus-online-retailer cookie divide isn’t the only observation Truste made after combing through the 2,048 cookies it tracked in October on the homepages of the top 100 most trafficked websites (according to online measurement firm

BlueKai—the data exchange that last year got in the business of helping advertisers target specific consumer segments like auto enthusiasts or young moms—was found to drop the most cookies of any third party, leaving a trail of 93 cookies, outpacing comScore’s 78.

“It’s shocking that BlueKai is more prevalent than comScore. The fact that cookie-targeting is occurring more often than analytics, I have to say it’s surprising to me,” Trilli said. In keeping with the prevalance of advertising over analytics, Google/DoubleClick came in third with 49 cookies, followed by Gannett/PointRoll with 39.

Update: Since this story was published, BlueKai contacted Adweek, arguing that not all of its cookies are used for third-party data collection. A spokesperson claimed that BlueKai also gathers first-party data to be used for site personalization and analytics. 

Of the total number of cookies Truste detected, 49 percent were dropped by third parties, and of those third-party cookies, 94 percent were persistent, compared to 65 percent of first-party cookies that were persistent. “It’s to be expected that more third-party cookies would be persistent because they are designed to be across websites. The richer the profile associated with a cookie, the more valuable it is,” Trilli said.

Might alll this attract FTC scrutiny? Not necessarily, said  Trilli. In fact, Truste found that 80 percent of the third parties it encountered were members of the Digital Advertising Alliance’s self-regulatory program. And of that remaining 20 percent, “a lot of those players can’t provide icons because of the nature of their products,” Trilli said, pointing to BlueKai as one example. “The DAA’s working,” he said.