Nielsen: "Facebook Has Become Our Panel For Measuring the Online Universe"
Description:In tabulating viewership of TV shows, Nielsen has long relied on a "panel" of several thousand consumers who have a little box that monitors their viewing. To build ratings around the world's billions of Web pages has proven far more difficult and Nielsen had been able to monitor about one percent of the online universe using its online panels. Last year, Nielsen partnered with Facebook in a program called online campaign ratings.(3:46)