In Australia, overnight ratings figures continue to be the dominant measure of success and failure.

In Australia, overnight ratings figures continue to be the dominant measure of success and failure.

American television networks are pushing for greater analysis of television viewing, hoping to track audiences who watch TV shows across a whole month rather than the traditional "overnights".

Like Australian television, American television is ruled by the "overnight" figure - the rating which is delivered the following morning to networks from audience measurement agencies.

Despite the fact that it is the least illuminating ratings data available, it continues to generate the most media noise.

In Australia those numbers are delivered by OzTAM. In America, networks use the audience measurement agency Nielsen.

But CBS boss Les Moonves, speaking at this week's UpFront event in New York, showcasing new programming to prospective advertising buyers, said overnight ratings "are not quite as important as they once were".

"Every eyeball is now being counted," Moonves said. "Overnight ratings, although still fun to read here at CBS, are not quite as important as they once were.

"The bottom line is, more people are watching television than ever before, in every possible way, and that only makes it better," he said.

In the US, ratings data is tracked overnight, and DVR playback is monitored across three (live+3) and seven (live+7) day windows.

Significantly in the US, the second group - the so-called "live plus seven" audience - are statistically the most attractive group to advertisers: they tend to be younger and wealthier.

In Australia, only seven (live+7) day data is measured, and it is rarely prominently reported.

Since 2012 some US networks have been analysing 29 day (live+29) data, with a view to measuring audiences across a whole month.

Internationally, other major broadcasters such as the BBC use similar audience measurement systems which track viewers through their web of owned-and-operated channels, across overnight, week and month-long windows.

In Australia, meanwhile, the overnight continues to be the dominant measure of success and failure, despite the fact that some programs are now drawing between a fifth and a quarter of their total audience from DVR playback viewing.

In some respects the push for more audience analysis is a response to the growth of online television platforms, which deliver content on demand and measure audience consumption across much longer windows. Most do not publish that data, however.

Moonves noted at the UpFronts that "everybody" wants to get into the content business.

"Even our friends in Silicon Valley are expanding from developing algorithms to developing television shows," he said. "We are happy to welcome everybody to this new content revolution."