The popularity of CNN's website may be the principal source of the cable news network's ratings plunge, the company's digital chief K.C. Estenson has told Adweek magazine. "Our audience is watching CNN in ways that are not detectable in the Nielsen ratings," Estenson said, noting that CNN Digital generates 110 million video streams per month and that CNN.com registers a billion page views a month, a quarter of which are on tablets and smartphones. Moreover, he noted, the online audience is 15-20 years younger than the TV audience. Estenson maintained that the success of CNN's digital efforts has been ignored by the press, which has focused on the ratings ascendancy of Fox News and gains by MSNBC. "When I see the ratings stories and I see CNN getting bashed on TV, there is a huge story being missed," Estenson told Adweek . "Our viewers consume media in a very modern media way. The traditional model works very well for Fox. That's not our audience. Our viewers are educated, affluent, sophisticated. They're global traveling citizens. The story about this brand is that its consumption habits are leading-edge." While CNN.com continues to lead its U.S. rivals online, it is also showing sharp declines in visitors and page views versus last year, according to online researcher Quantcast.