Joseph Blow, a man I don't know, is sitting down eating a muffin . . . right now.

I know this because he told me so, along with a couple of hundred other people.

I do not know Joseph Blow, but he is my friend. My friend on Facebook.

Joseph Blow is my friend because he is a friend (on Facebook) of someone else I don't know. Who is a friend of someone else I don't know. Who is a friend of someone I met briefly during a small business networking session three years ago in Poughkeepsie, N.Y. Someone to whom, in a moment of weakness, I gave my business card.

I have never attempted to contact Joseph Blow. He probably does not know who I am. But I know he is sitting down eating a muffin . . . right now. This gives me power.

I do not know what Joseph Blow looks like, because when I look at his Facebook profile there is a picture of a cartoon character where his photo should be. A cartoon character I also do not know. Joseph Blow does not own a digital camera. Or else he is incredibly ugly. Or he does not own a digital camera. And he does not respect copyrights. Which means he cannot truly be my friend.

Janet Doe, a girl I don't know, is also my friend. She is eating bacon and scrambled eggs for breakfast . . . right now (even though it's 8 p.m. my time). Janet likes to eat breakfast late. Or else she lives in Australia.

Because I am friends with Joseph Blow and I am friends with Janet Doe, Janet Doe will soon be friends with Joseph Blow. Because people with friends ask all of their friend's friends to be their friends as well. But I do not think that Janet Doe and Joseph Blow will ever be friends. People who eat bacon and scrambled eggs for breakfast are a different breed than muffin people. They vote for different political parties and have different tastes in art. This is well known.

Because Joseph Blow and Janet Doe are both my friends, it is difficult for people to tell which camp I fall into. Do I eat muffins or bacon with scrambled eggs for breakfast? Nobody knows. I'll be damned if I'm going to tell them. Let them guess.

What does this have to do with running a business? Because there are books — lots and lots of books — that say you should create profiles on Facebook and other social networking sites and collect lots and lots of friends. Because then you can sell stuff to them. Lots and lots of stuff. It is called a "Web 2.0 strategy," or, more simply, "viral marketing." If your friends buy your stuff, then their friends will buy your stuff, and their friends and so forth. Before long everyone on Facebook will buy your stuff. And you will be very, very rich.

But there are two problems with that.

First, it does not follow that because Person A likes muffins for breakfast, and Person A and Person B are friends on Facebook, that Person B likes muffins. Person B may actually hate muffins, and will hate you for trying to sell him a muffin on Facebook. Because all his true friends know he is a He-man muffin hater, and always has been.

Second, to have friends one must be a friend. If you buy my stuff on Facebook, because you are my friend, then I will have to buy your stuff on Facebook, because I am your friend. In the words of Stevie Wonder, "that's what friends are for." But I may not want your stuff. I may actually hate your stuff. But I don't want to make a friend angry, because then you will tell all my friends on Facebook that I am not a true friend. So I will buy your stuff. With the money you paid me for my stuff. And I will then sell it on eBay. Net gain: zero.

Marketing on Facebook and other social networking websites is a very tricky business. Most people are so happy to have "friends" they admit anyone who asks. If you allow people you do not know to become your social networking "friends," you open yourself (and them) up to all sorts of mischief. Friends do not "spam" friends, or offer them goods and services they don't need or want.

Your "friends" on social networking websites should be only (1) people with whom you have an actual personal or business relationship, (2) people you like, respect or admire, and/or (3) people you care enough about to want to know what they eat for breakfast. If anybody else asks to be your friend, hit the "ignore" key.

Someday I will kill Joseph Blow (remove him from my "friends" list on Facebook). But not right now. He is sitting down eating a muffin . . . right now . . . and I want him to have a good last meal.

Cliff Ennico (cennico@legalcareer.com) is a syndicated columnist, author and former host of the PBS television series "Money Hunt." This column is no substitute for legal, tax or financial advice, which can be furnished only by a qualified professional licensed in your state. To find out more about Cliff Ennico and other Creators Syndicate writers and cartoonists, visit our Web page at www.creators.com.

COPYRIGHT 2008 CLIFFORD R. ENNICO.

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