TV audience ratings agencies have been talking about near real time online measurement for some time, but so far it has largely been confined to adverts where the commercial incentives for getting going are greater. Now Nielsen, the biggest TV ratings agency of all, has launched a pilot program in the US to count audiences for content viewed online from the main Networks. Commercial launch in the US is slated for later in 2013, followed by extension to Nielsen’s overseas markets. The three month Nielsen Digital Program Ratings trial begins later this month with the five major TV networks participating, that is NBC, CBS, ABC, Fox, and The CW, as well as online portal AOL. This follows AOL’s announcement in…