EITHER people aren’t watching television as much anymore, or technology has gotten so advanced that it’s become impossible to track.

More than 2.5 million fewer people were watching ABC, CBS, NBC and Fox than at the same time last year, statistics show.

According to Nielsen Media Research, prime-time viewership for the four biggest broadcast networks was down to 37.6 million people, from 40.3 million during the same period in 2006.

This could be a result of more DVR, streaming on the Web, downloading on iTunes and iPods, and even DVDs.

And without numbers to show, there are fewer advertisers.

“People are not consuming less television, they’re watching it in different ways, and the measurements haven’t caught up,” said Alan Wurtzel, NBC’s chief research executive.