Back in 2011, Facebook launched the Subscribe button, which allowed users to sign up to receive updates from other users' updates - either all of them, most of them, or only the important ones. Users can Subscribe to their friends, but the main purpose of the feature was to give Facebook its own "follow" functionality, similar to a service like Twitter. Facebook users can subscribe to journalists, celebrities, and other users that they aren't necessarily friends with in order to receive updates in their news feeds.
Now, according to a Marketing Land, Facebook is testing a Subscribe button on pages.
A Facebook spokesperson has confirmed the test, which is only able to be seen by a handful of users:
We are currently testing the ability to subscribe to Pages with a small group. This feature allows people to receive updates from Pages without liking the Page. We have no further details to share at this time.
As you would expect, the Subscribe button is appearing right next to the Like button on the top of a page's Timeline:
Of course, the main difference in liking a page and subscribing to a page would come in the form of perceived support. Users could keep track of the updates of certain pages without publicly declaring a "like" for them. Plus, subscriptions are unlikely to show up as a news feed story, so unlike with likes, users could subscribe to pages' updates without their friends ever being any the wiser.
Of course, from the standpoint of the page owners, the difference between likes and subscriptions could be confusing, and a subscription would definitely not be as coveted as a like.