Around YouTube headquarters, there&'s a stat that management likes to throw around to make it clear that the company isn&'t resting on its laurels. No, it isn&'t the fact the site is the world&'s second largest search engine or that its users upload 35 hours of content per minute. It&'s that the average user spends around 15 minutes per day on YouTube. That would be an impressive amount of engagement for just about anything else, but it pales in comparison to the five hours that people spend sitting in front of their TV sets watching cable (yes, seriously). And make no mistake: YouTube wants to take some of that time for itself.

Today, the site is taking an important step toward that goal as it improves its Leanback product with a key new feature: personalized channels. LeanBack, which launched in July and is integrated into Google TV, lets users hit &8216'play&' and then sit back and watch an endless stream of YouTube content with no input required. In short, it&'s YouTube TV. And now it&'s personalized TV �a4���a4�a4s��something that no cable network out there can match.

Before now Leanback has had the concept of channels, but these were primarily built around social activity from your friends and videos curated by YouTube. Now the site is going to try to learn what you like and generate new personalized channels accordingly. These channels will show content that&'s relevant both to the things you&'ve told YouTube you like, and topics that YouTube thinks you&'ll like (for example, if you build a channel around funny cat videos, it may start throwing some funny videos without cats into the mix).

The feature acts a bit like a Pandora for video. It learns about your preferences based on both your explicit actions (like hitting the &8216'thumbs up&' button) and implicit signals, like which videos you&'ve watched and how long you watched them for. You can also manually add new topics and keywords to adjust the kind of content YouTube will display.

It sounds great, but I suspect it&'s going to be a long, slow process for YouTube to really get people used to the idea. Issue number one: YouTube Leanback is supposed to let people sit back and watch an endless stream of relevant content' if they&'re doing that, I doubt they&'re going to want to hit the &8216'thumbs up&' or &8216'down&' button unless it&'s effortless (at this point no Google TV remote has a dedicated button). So YouTube will probably be relying primarily implicit signals for now.

But more important, Leanback is introducing users to an experience that is very different from YouTube itself. Yes, YouTube has long offered suggested videos, and has countless channels of content, but this notion of leaning back and just watching is something that will take some getting used to. That said, YouTube reports that Leanback users are consuming 30 minutes at a time �a4���a4� twice as much as they do using the normal site �a4���a4� so obviously it&'s working for some people.

And it won&'t take long until a lot more people are on Leanback. YouTube is already integrated into Google TV, and it has apps on other HTPCs as well. The company has also started searching for a Product Manager to lead its &8216'YouTube on TV&' projects, whose responsibilities include managing relationships with both content and hardware partners. In other words, YouTube Leanback (or a related product) is going to be popping up in a lot of places over the next few years. And once it nails this notion of personalized video content, it&'s going to be tough to go back to plain old TV. CrunchBase InformationYouTubeInformation provided by CrunchBase