The decision to expand beyond traditional TV happened after a meeting last Tuesday by the What Nielsen Measures Committee. They have been meeting for almost a year and the group is made up of representatives for major TV networks, local stations, cable networks, advertising agencies and some big brand advertisers.
The plan is set to begin by September when the new TV season begins.
Currently, if you watch RAW on tablet, Xbox or Hulu Plus, Nielsen doesn't have a way to measure that. The new plan will correct that problem and will change how TV ratings are measured in the future.