This is a file photo! (Paul Sakuma/AP)

True, nobody can quite agree how to mon­etize Facebook. But never mind that. It is common knowledge that it contains hundreds of millions of users. Each user has, on average, 229 friends, 22 percent of whom he or she met in high school. And through friends of friends, we can each reach something like 150,000 people. It has to be worth something.

In the mean time, Facebook is less a country than an ecosystem. The jungle has its own laws. It is not a particularly mean jungle — 80 percent of friend requests are accepted — but like any good ecosystem, it has its recognizable types. And before you invest, consider what you’re getting.

The Eight People You Meet On Facebook:

The Liker: You haven't spoken with this person in the flesh in over three years, but somehow he or she always winds up liking your statuses. You aren’t even sure what country this person resides in, if you have to be completely honest.

The Infected: This person always seems to be offering you FREE IPADS. If zombies ever come for us, steer clear of him. He's going to be among the first to go.

The Tagger: If it weren’t for the Tagger, none of those vacation photos would ever wind up with your name on them. Your attitude towards this person varies, depending upon the lighting and your state of undress.

The Oversharer: I had no idea so much was going on in your life! Didn’t I see you eight minutes ago? How have you updated six times? Another blog post? Landsakes, you don't even have that many thoughts! (These are rare; only 6 percent of total users, but 13 percent of users 18-to-22. Also, I apologize.)

The Lurker: You have no tangible proof of this, but you feel confident that the only reason this person keeps showing up in the ten pictures to the left of your profile is that he has been sitting there reloading the page, eating ham and noiselessly weeping.

Here is what Facebook says: “We highlight your friend list. By default, a changing selection of all your Facebook friends always appears under the Friends heading in the left column of your profile. This selection might include friends who you interact with the most in Wall posts, comments and mutually attended events. However, Facebook does not select friends to show based on whose profiles you choose to view or who you interact with over messages and chat. 

Your family and relationship partner appear here, too.”

“Might” is a very broad word.

These might be the friends you interact with the most. Or it might be the friends who are most likely to be dangerous cultists. Really, Facebook is saying, you have no way of telling.

It might be something entirely different, like the ten people whose recent Likes suggest the two of you would have healthy children. I mean, if Target can tell you’re pregnant, Facebook could certainly pull off a little matchmaking.

The Trainwreck: “Just discovered that tap water controls minds!” this person posts. You would have unfriended her years ago, but the pictures of her misspelled tattoos and her frequent check-ins at Olive Garden afford a certain grim satisfaction.

The Ranter: This person, like the Yellowstone Volcano, remains silent for long periods of time, then spews everywhere, scalding anyone within reach. Not the best speller in the history of mankind.

Our Mutual Friend: This person somehow knows everyone or nearly everyone you know. His profile image is an anthropomorphic Disney character, but you feel pretty sure that if he ever posted a real picture, you would know the guy. Then again, all your common friends say the same thing. Sometimes a variant of the Liker.

Did I miss any? Leave them below!