Interest lists were introduced around the same time that the Facebook timeline was introduced for personal profiles, but not many users seem to know about them. The most popular lists only have around 20,000 subscribers, which is miniscule compared to the amount of Facebook users out there.
What are interest lists, you ask? Essentially, they aggregate status updates from fan pages and personal profiles (using the subscribe feature) and display them in a contained news feed. This news feed is completely separate from the news feed that displays posts from your friends, subscriptions and pages you've liked. These lists allow you to separate your existing news feed into whatever categories you want. Plus, you don't even have to Like or subscribe to a page or individual before putting them into a list. You can also subscribe to other peoples' lists.
For example, you can pull up a list of newspapers on Facebook every morning and go through the daily news while you eat breakfast. When you are done reading the news, simply close the list and start browsing your regular news feed. It seems like a great feature, so why aren't more Facebook users taking advantage of lists? I have 3 theories.
First, Facebook has not been promoting the feature heavily. It is located at the bottom of the left column of your news feed, right below subscriptions (which is also a feature that not all Facebook users are aware of). As far as visibility goes, only keen-eyed Facebook users would notice it. Second, lists require effort. Creating your own list requires browsing for pages or individuals to add, which probably takes a couple of minutes at most. However, in my opinion those couple of minutes are enough of an effort to turn off many users. Even subscribing to other users' lists is not completely hassle-free; there is the matter of actually pulling up the list every time you want to view it. Finally, not all Facebook users need lists. Many users only interact with their close friends and family on Facebook and have no need to categorize them any further.
Personally, I fall under the second category. I could subscribe to lists that others have made, but not everyone on the lists is relevant to my interests. I have a couple of ideas for lists in my head, but I never want to put aside the time to actually create the lists. I was going to create a Facebook list today, but then I decided to write a blog about it instead.