The Facebook "Like" feature is nothing new - for months now users have been able to "Like" a user's status update or shared content. When Facebook launched the feature way back, the said that the "Like" button was designed to take the place of short, one-word comments that indicated that a user liked something. In the months since the launch of the original "like" feature, that simple, four-letter word has come a long way. Last month Facebook dramatically extended the reach of the "like" feature, allowing users around the world to "like" content on the web, like a blog post or, to use Facebook's original example, a particular pair of Jeans on Levi's website.

But through all of these revisions to the Facebook "like" feature, there was always one glaring absence, one huge thing that you simply couldn't "like," no matter how much you wanted to. You could "like" a user's original status update, but you couldn't "like" the comments that were made on it. For many users, the absence was palpable. In many groups of friends, the comments on a particular status update are more "likeable" than the original status update itself, but users didn't have any way to express their feelings about comments.

All of that changed this week when Facebook announced in a blog post ("I Like Your Comment") that users now have the ability to "like" the comments made by other users. A quick review of the Facebook News Feed shows that this new feature is already available to nearly all Facebook users, although many users haven't even figured out that the new feature is available.

In many ways, this latest revision of the "like" system nearly completes the feature. Users are now capable of "liking" almost every kind of content that they want to - content on other websites (which have enabled the "like" feature), content shared on Facebook by other users, status updates, comments - just about everything on Facebook. The only thing you can't do on Facebook is "dislike" something, which is a feature that Facebook users have been clamboring for for years now.

It's unlikely, however, that Facebook will ever enable a "dislike" button, since the goal of the "like" feature is specifically to increase the amount of content that people view on the social network, and a "dislike" button would work entirely against that goal.

Considering that most Facebook users never actually read the Facebook blog, it's going to be a few weeks before most people notice that small "like" button next to comments in the timeline - but it's a foregone conclusion that they will eventually notice it, and when they do, the new "like" feature is going to see heavy usage - and will hopefully cut down on the number of one-word replies in just the same way as the original "like" feature did, helping to clean up the timeline and making things easier to read.