Fewer people in the United States are watching prime-time television on Thursday nights, as changing viewing habits and increased competition erode audiences on the evening that has for decades defined by must-see network television shows. One study suggests a third of the adult online population in America no longer selects its programming from the traditional television schedule. For the first time in decades, pay-television subscriptions are falling. Comcast is losing basic cable viewers faster than it is gaining digital television customers, but claims of cord-cutting may be overstated.

The Wall Street Journal reported Nielsen research that the audience for the first four Thursday nights of the television season is down over 4% on the previous year among those aged 18-49, for the first time in many years falling below 50 million. The combined audience for Thursday night shows watched the evening of transmission is down 14% from last year. The number in that age group watching television any night of the week, live or recorded, is down 2.7% so far this season.

The audiences for many prime-time shows on the main networks are shrinking in the face of competition from cable networks and other forms of viewing. It may be too early to call the end of appointment to view television, but viewing habits are changing.

Recent research suggests that nearly 56 million American viewers are “off the grid” — that is to say no longer selecting their viewing from the live channel schedule. They represent nearly one third of the adult online population in the United States.

They value choice, convenience and control. For them it is no longer a question of what is on, but what is available.

Say Media and IPG Media Lab announced the results of a study by comScore of over a thousand online consumers, finding that a fifth of them watch less live television than a year ago. They reported streaming video more than four hours a week, which is more than they claimed to watch live television.

Of the survey respondents, 13% claimed to have completely opted out of live television, not watching it all in the previous week, receiving programming through their DVR, on DVD or online. Of these, 30% were in the 18-24 age range. On average they watched over 20 hours of video a week, but half of that was online.

Comcast lost 275,000 basic cable television subscribers in the last quarter and gained 219,000 digital video customers, a net loss of 56,000 video customers. It has 820,000 fewer video customers than a year ago. One might suspect that this is further evidence of cord-cutting.

According to Comcast exit interviews, those that are dropping basic cable are not necessarily turning to online sources for their programming. They are turning instead to broadcast television, going over the air rather than over the top. One consequence of analogue switch off may be greater awareness that high-quality digital signals are freely available over the air.

However, despite the economic climate, Comcast still has 1.4 million more digital video customers than a year ago, around 19.5 million homes. Comcast also has a million more high-speed internet customers than a year ago, approaching 16.7 million. Even if customers are dropping cable television to explore online alternatives, they will still be buying broadband.

In its efforts to defend its television territory, Comcast has also re-launched its TV Everywhere service, Xfinity TV. The service is now available to all Comcast television subscribers, even over other broadband networks, anywhere in the United States with a web connection. With programming from over 90 providers, it offers around 150,000 video choices online, free to Comcast Digital Customers.

There is certainly evidence that television viewing behaviour is changing, but it is complex picture. While people may be viewing in new ways, in many cases they are actually watching more rather than less programming as a result of new delivery technologies.