Would you trust a social media friend with your money? Your home? Your significant other? Your children? Your life? Your answer to those questions will determine whether or not you feel that friends, as used in social media, are friends like you had in school or if they're better labeled as something else.

The social media friend is the key ingredient that makes digital media social. Social media users have the ability to create a user profile which lists relevant information about them. The user can then select other users to be friends, followers, buddies, contacts, or some other relevant noun. Showing that you are a friend of another social media user indicates that there is some form of relationship between the two of you. The connection may be weak, but it's important enough for you to tell the world about it.

The thing is that sometimes the people that we identify as social media friends are people we barely know or that we've never met in person. The act of befriending another person on sites like Facebook, Digg, StumbleUpon, or Twitter can be tactical moves as often as they are signs of genuine affection and solidarity.

Let's take a look at the major roles that social media friends can play – some are friendlier than others:

Friends and family: yes, some of the people you encounter within social media will be people that you really do know. These folks can be a source of love, companionship, and empathy. Facebook's Friends were intended be your real life friends. Kind of an appropriate name, don't you think?

Information sources: social media is all about sharing stuff. The basic currency of this realm is shared ideas and information. Want to know about the pros and cons of a particular car, computer, vacation resort, or restaurant? Throw the question into social media space and you can get a multitude of responses. Social media users like to give stuff away. Giving away information and otherwise being helpful is an effective way to attract social media users; so is being nice.

Connectors: in The Tipping Point, Malcolm Gladwell describes a class of influencer called the connector. Connectors collect people. Not literally, but they enjoy meeting and learning about people. Connectors like to introduce people who they think will benefit from meeting each other. This kind of social media user (not unlike the host of a party, conference, or meeting) is a great source of referrals, introductions, and connections to other people. This is an important and sometimes underappreciated role in any social environment, both in personal and professional matters.

Prospects: whether it's potential clients, worker bees, or evangelists, social media provides a way to collect people for future use. This is a cynical way of looking at the "tribe" concept that's currently espoused by marketers and by no means is it the norm. But it's out there and it's personified by people who add 50,000 plus friends in Twitter, all in the hope that a few of them will follow back and become a captive audience.

Groupies: just like the fanatical gals (or guys) who follow rock bands around and fulfill some of their more basic needs, prominent social media users collect followers who are there to witness (and celebrate) anything their idol says or does. OK, perhaps that's a bit harsh, but there is a grain of truth to this. People will follow other people in order to feel slightly closer to someone who they admire or worship. I'm not immune to this. I follow Wil Wheaton on Twitter because he posts quirky and interesting things. He follows far fewer people than follow him and I'm one of the many who haven't been followed back. By contrast, people like Robert Scoble and Jason Calacanis maintain ratios much closer to 1:1. They're all busy people, but some people make a point of returning the following favor. Others don't and that's fine, too. However, some people seem to get a thrill out of building up a legion of followers.

While Friend is a useful "catch all" term used in social media, it doesn't have a single meaning. Facebook's Friend functionality does a good job of qualifying the relationship between its friends by several categories, including family, school, and work connections. Tara Hunt, aka Miss Rogue on Twitter, suggests that the XFN distinctions to classify types of friends would be a good addition to social networking sites. "Very few of my thousands of relationships actually fall under true friendship," says Hunt. When you think about theories like Dunbar's number, which posits a limitation of approximately 150 significant connections or relationships that each person can have at one time, Hunt has brought up the logical point that it's very difficult to have huge numbers of meaningful relationships with hundreds or thousands of social media friends.

The term friend will remain in social media for a long time to come: it's embedded into social networking culture. I think that contact is really a better term to use because it's more consistently accurate. Contacts are people who know each other, even if only superficially, and they've given each other permission to reach out and communicate to each other. Contacts can also be real friends. However, as I asked at the beginning of this article, would you trust a social media friend with something that's precious to you? Trust is not a default – it needs to be earned. Maybe that's the best test to use when trying to figure out if your friends are really friends, online or offline.