SAN FRANCISCO » Netflix is introducing a long-awaited feature that will make it easier for the Internet video service to track and analyze the viewing habits of people sharing the same $8-per-month account.

The tool coming out today can splinter a single Netflix account into up to five different profiles at no additional charge. The Los Gatos, Calif., company is hoping its 37.6 million worldwide subscribers will use the profiles feature because it will help Netflix’s recommendation system gain a better understanding of the different tastes of viewers using the same account.

The feature initially will only be available on Netflix’s own website and several other viewing outlets, including the iPad, iPhone, Apple TV, PlayStation 3, Xbox 360, Apple TV and some smart TV models. It may take up to two weeks before the profiles choice pops up in these options. Profiles should be available on the Wii console before the end of August and on Android devices before the end of the year. Netflix subscribers who use Netflix on Roku’s set-top box probably won’t be able to use profiles on that device until early next year.

Until now, deciphering the preferences in large households could be tricky because Netflix’s system couldn’t distinguish between when a 50-year-old dad was watching its Internet video service and when his 10-year-old girl might be viewing under the same account.

"If the kids have been watching a lot of ‘Shaun the Sheep,’ that doesn’t particularly help us help you find the next gritty drama to watch after they have gone to bed," said Neil Hunt, Netflix’s chief product officer.

Profiles will now make it possible for several members of the same household to click on their screen name to get customized recommendations, based on what they have previously watched and seemed to enjoy in Netflix’s library of movies, old TV shows and original programs. Netflix relies on viewers’ own ratings of video, as well as computer-driven analyses of the genres previously watched.

Netflix Inc. considers its recommendation system to be one of its biggest advantages over rival Internet video services run by Amazon.com Inc., Hulu.com and Redbox. As long as Netflix keeps steering its subscribers to videos that they like, the company figures customers will be less likely to cancel the service.

Even though it’s often analyzed a jumbled mix of viewers, Netflix’s recommendation system apparently is hitting a sweet spot more often than not. The company says about three-fourths of the video watching on its service is driven by its recommendations.

The new profiles can also be used to link to each user’s Facebook account. That connection allows Netflix members see what the other people in their online social network have been watching on Netflix, too.