How not to use facebook to push your online activities is a more appropriate question.
Don't do what this bozo did. Randomly add friends and then spam their wall.
If you are going to use social networking sites to try to push your online sales, please do so with a little panache and class. Any idiot can randomly add people, spam them, annoy the hell out of followers, and achieve very little. Like anything that earns you money, to do it properly needs a little more hard work.
The great thing about social networking is the ability for viral marketing. If you spam one persons wall with something cringeworthy like "buy a website from me, i'm great" - it all ends there. You may send your spam to 100 walls, but all that will happen is those 100 people delete your post and you receive some kind of ban.
Or, you can get a little creative.
What if you create something which inspires your followers to post your creation on their followers walls? Say you have 100 friends who have 100 friends and so on. Your creation passes from friend to friend, wall to wall because you have created something which people actually wish to share. This isn't spam, it is what social networking was created for - sharing. The trick is to create something which others will actively share, and then also cleverly piggy back some way of promoting your services into it too, if you can master that art, you will have more traffic then you know what to do with.
Now, it's easy to say what is needed to create a viral marketing campaign, actually doing it is another matter. A lot of people share jokes, pictures, etc, which work. Others create contests with some kind of incentive to share the content, such as you will win a prize.
Unscrupulous people create campaigns which prey on the mind of social network users, such as the little boy with cancer who needs an operation, and some made up organisation will donate 10pence for every share or like. Unfortunately, that kind of viral marketing also works, because a good portion of the online population are stupid.
Whatever you decide your method will be, you need to make sure it catches on. Get people sharing your content while you sleep. If you can wake up to 5,000 notifications and 50 friend requests per day you are doing something right. Look how I achieved this feat......I posted this status update on facebook at a time when I only had 40 friends. Within 2 weeks I had over 2000 friends and this had been shared thousands of times, getting over 100 messages per day.
So, you can be a clueless spammer and get no results, or you can put some effort in and reap the rewards. Admittedly, this little con did not earn me any cash, but what it does is highlight how easy it is to get people to share content on social networking sites. If you get it right, it will earn you more in a day then a whole lifetime of spamming will get you.