Facebook

Just a day after announcing sweeping changes to friends lists, Facebook has announced another new feature, called the subscribe button.

Facebook users will soon see a new "Subscribe" option on some other people's profiles. When clicking the button on a friend's profile, users will have the option of subscribing to all, most, or only important updates the other person posts to the site. Those updates will show up in the user's news feed.

To make things a bit more interesting, Facebook is also letting people subscribe to news feeds of users they're not friends with. Upon doing so, they will see the public updates the person has shared on their profile. And like with friends, users will be able to determine how many of those updates they will see in their news feed.

If Facebook's new subscription option sounds familiar, there's good reason for that: it's rather similar to Twitter. On Twitter, users have the ability to follow others, including those they don't know, and see their public updates in their timeline. Now, with the subscribe button, users can do the same with Facebook.

What's more, both services have similar privacy features. If users want to allow others to subscribe to their public updates, they will need to go to their Subscriptions Page and click "Allow Subscribers." However, those who don't want to share their updates can just ignore the setting, which stops a subscription option from being displayed. Twitter has a similar function in place, which allows users to protect their tweets and only share them with those they allow to see their updates.

Facebook has had a busy week. Just yesterday, the company announced that users will have the ability to more efficiently group friends into lists. The company unveiled an option that lets users put friends into "Close Friends" or "Acquaintances" lists to quickly separate the kind of content shared with those groups. Another new addition, Smart Lists, sees Facebook automatically creating lists for users. Those lists will initially be created around workplace, school, family, and city.

Facebook's new subscribe button, which will be available across the social network in "a few days," is the latest entry in what the social network's CEO Mark Zuckerberg called in July, "launching season 2011." Zuckerberg kicked off the season this summer with the launch of video calling and group chatting.

Update at 10:50 a.m. to include more details.