Facebook has changed, and continues to change, what it means to be a “friend.” Previously we may have used other words to describe relationships such as acquaintance, classmate, coworker, and so on. However, Facebook now clumps all of these people under the heading of “friend.”

Mark Zuckerberg, Facebook’s creator and CEO, commented that just choosing to use the word “friend” means that people are much more open to sharing personal information. If users consider everyone in their networks to be “friends,” then they are more willing to open up on the site.

Obviously what you share on the site is always up to you. You can choose to not type a post or upload a photograph. What is important to remember, however, is that no matter how you have created your friends list, Facebook is always a part of that list. That is, Facebook is also able to view everything you add to your profile and use that information as they wish.

Each user having many friends is important to Facebook because they can advertise to you through your friends. If a friend “likes” Bob’s Diner, her name and profile picture can then be used in an ad on your newsfeed. Learn more about Facebook ads and change your social ads settings here.

This is essentially what is called “word of mouth” advertising, just in a new way. Traditional word of mouth advertising is telling someone about a company that you like. For example, your friend might tell you that she really enjoyed eating at Bob’s Diner. This is the best kind of advertising because someone you know has personally recommended a company. You are much more likely to try the place since a trusted person told you about it. To see how Facebook describes the idea to their investors, check out this video.

Facebook labels these ads “Social Ads” and claims that companies see 50% more ad recall when their ads are “social.” So, even though your friend isn’t actually telling you to visit Bob’s Diner, because she “liked” their page, her “recommendation” appears on your newsfeed. This is great for Facebook and the companies who advertise on the site because they don’t have to rely on people actually remembering the company or telling their friends about it. Once your friend “likes” the site, she is “participating” in word of mouth advertising whenever Facebook’s algorithms see fit. This is unlike offline—eventually your friend may stop talking about Bob’s Diner, forget about it, or even stop liking it.

Facebook actually provides a good amount of settings for grouping friends and limiting certain content to certain friend “lists.” Although it can be time consuming, setting up these lists now will allow you to more easily manage the different social contexts that you have offline. For example, you can break your friends down into lists such as family, close friends, co-workers, or whatever categories that you come up with. Friends can live in more than one list. This way, when you create a post or upload a photo, you can easily choose who can see your new content.

To create your friend lists, go to your profile and click on “Friends.” Next, find the friend that you want to add to a list. Hover your mouse over the box that says “Friends” to the right of his/her picture. When you do, a menu will pop up. Facebook may have suggested lists for you. But, you can also click on “Add to another list …” Another menu will appear with an even larger selection of suggested lists and perhaps lists that you have already created. You can also scroll all the way to the bottom and choose “New list.” Name your new list and continue on!

Now, when you are about to post any new content, before you click “Post,” you can choose which friend lists will be able to see your content. Click on the menu and a drop down box appears. From this menu choose “Custom.” Here you will be able to add the friend lists that you want to view your content, along with specific people. You can even choose which lists or people will be blocked from your post.