A family watching television in their home, circa 1955. Now viewing on tablets will factor into TV ratings.

Story highlights

Nielsen, which measures TV ratings, will begin tracking online-viewing habits

A new software development kit will be released to clients in November

While most people still watch TV on televisions, a growing number stream shows online

CNN  — 

A TV show can be wildly popular online, inspiring binge-watching marathons and feverish Twitter chatter, but it’s still the number of people turning in via a regular television set that are counted most by networks.

In a sign of our increasingly connected age, the Nielsen Company will finally add streaming viewers to its influential ratings of who’s watching what on TV. The new ratings will collect data on people who watch their sitcoms, dramas and crime procedurals on computer, tablet and smartphone screens.

Nielsen first announced it was testing programs to track streaming viewers in April. In mid-November, it will release a software development kit that clients can use to figure out who’s tuning in online.

Nielsen ratings are used to figure out how many people are watching a show and the demographics of the overall audience. Networks use those numbers to determine how much to charge for ads and even to help make scheduling decisions, such as canceling shows that pull in dismal numbers.

Television sets are still the primary way people watch TV, but online viewers are growing fast. They stream shows to non-TV screens, such as computers, tablets and smartphones. Their viewing habits are different, too: They consume entire seasons in single sittings and catch up on “Daily Show” clips during commutes. The streaming and mobile audiences tend to skew younger, a coveted age group for advertisers.

Nielsen typically tracks demographics such as age, location, gender, race and income. To gather that type of detailed information about online viewers, the company says it will match demographic information with data providers such as Facebook that already collect that information about Internet users.

Not all online views will count as part of the main Nielsen TV ratings.

Shows that don’t include the same ads online as on TV will be counted as part of separate Nielsen Digital Ratings. Shows streamed directly by networks through their own sites and apps typically include the same set of ads, and those viewers are counted towards the traditional Nielsen totals.

This is the latest attempt by Nielsen to catch up with current digital-media technology. Earlier this month, the company announced it was launching Twitter TV ratings, tracking the number of people tweeting about a show and how many people were reading those tweets.

Nielsen ratings are typically collected in several old-fashioned ways. For example, it still has households record their viewing habits in handwritten diaries, documenting any show they watch for more than five minutes.