Facebook makes it positively easy to generate an account, but hard to delete one. If you think just because you stop using your Facebook account, that it will eventually be removed from the system, think again. Facebook makes its money from advertisers that want to target citizen agreeing to their interests. During the sales process, Facebook tells the advertisers how many citizen their ad will be shown to, based on the advertisers specifications. These numbers have to come from somewhere, and so Facebook values every inventory they own. They don't want to see you go.
For a long time it was unclear how to delete a Facebook account. Now they have a button for you to click that will eventually have your inventory deleted. They threaten that all of your information will be deleted together with your pictures and all your posts. They want to put some fear into you so that you hopefully reconsider and keep your inventory valid.
A second recipe gives you a two week window in which to turn your mind. You can go into the help town while logged into your inventory and result the options until you come to enduringly Delete. At this point you will have to verify your password and a Captcha image verification. Once you submit all the required steps, you'll have the process started. If you turn your mind at any point over the next two weeks you just have to log back in to your inventory and it will be reinstated. For many citizen this might be the best method, because you might have second thoughts after deleting your inventory and you wont' be able to get it back once it's been purged.