For the first time in 20 years, the number of American homes with TV sets in them has gone down.

The Nielsen Company, which takes TV set ownership into account when it produces ratings, will tell television networks and advertisers on Tuesday that 96.7 percent of American households now own sets, down from 98.9 percent previously.

Nielsen blames this trend on a couple of things. One is poverty, because the new high-definition sets cost more and require pricey cable. The other, as you might have guessed, is the internet, which feeds the young 'uns a steady stream of favorite shows directly to their computers. But should then computers be factored into consideration when counting "TV households?"

"We've been having conversations with clients," said Pat McDonough, the senior vice president for insights and analysis at Nielsen. "That would be a big change for this industry, and we'd be doing it in consultation with clients if we do it."

If it means juicing those ratings reports for advertisers, you can bet the networks are pushing for a yes. [NYT, photo via Shutterstock]