Is Netflix a friend or an enemy to traditional television?

On one hand, the streaming service has added billions of new dollars into the television business in recent years, building up its offerings by licensing programs from TV groups. But as Netflix increases its total number of subscribers, some analysts and industry executives are starting to voice a concern — that a steady rise in streaming is fueling the deterioration of traditional TV audiences and related ad revenues.

That was the question media executives grappled with on Monday at the UBS Global Media and Communications Conference. Against the backdrop of a 3 percent decline in television viewing so far this season, David Poltrack, chief research officer at CBS, unveiled research showing that streaming on Netflix and other services has started to cannibalize the amount of time viewers spend watching traditional television. Households with Netflix watch significantly less traditional television than homes without it, he said.

“The growth of streaming is seen at this point to be the major disruptive force in the media landscape today,” he said.

Netflix and other streaming services are greatly reshaping both how people watch television, as well as the broader economics of the TV business. Underlying that change is a shift away from watching television with ads to streaming television on services like Netflix that have no ads. Those viewer declines come despite an increase in original network programming.