Don't Ever tell them about your company.
People join Social Networking Sites because they want to meet people, or they want to promote their business (just like you). Yes, some people go there to find out about opportunities but they are a minority.
So if most people are not looking for a company or they are in a company, Why would you tell them about your company? That will just turn them off.
Social Networking Sites are about building relationships. As you get to know people they will begin to trust you. You will become friends. So do just that. Get to know people.
Don't post your link or e-mail them some ad about how great your business is. Instead let them find your link in your signature or in your profile.
If you are networking correctly and really caring about people, I promise you people will be wanting to check you out.