There are two schools of thoughts on this.
One is more of a hard core, in-your-face, almost used-car-salesman-y method. Some say using the first method goes directly against the spirit f why social networking sites were created.
The second school of thought is more of a long-view, careful approach. Some say that it’s too touchy-feely and not profit-oriented.
The truth is you have to look at your market, look at each method, and decide which one is right for you and your business. I find the second one much more profitable and effective, but then, my audience is fellow business owners, who already have thriving businesses and want a solution.
If your audience is the “get rich quick” or “lose weight now” crowd, you probably want to go with the first method.