I actually sold one of my products and decided to be stupid and look them up on Myspace. She was actually a super hot blonde girl buying one of my weight loss products. I was like: WHAT!? - dang. Am I the only one that does this? I know it sounds stupid but...
aside from the slightly voyeuristic way in which you described doing this that sounds like an AMAZING marketing tool to me. Think about it, people put EVERYTHING about themselves on their myspace (why, I don't know). If you are able to look up a large percentage of your buyers on places like myspace you have access to every single piece of demographic and marketing information you could ever need. You should be able to laser target your marketing like never before. Do you know how much real companies pay for that kind of information.
I've done that too, but only for my own product. It's actually kind of interesting customer research if you think about it. I too was surprised to find a girl that... didn't look to me like she needed to lose any weight. But then I realized that many of the people who buy these products arent trying to lose 100 pounds - but maybe.. 5 pounds. So they can look extra skinny like some Hollywood star. That's the sort of crazyness that's going on these days. But it's something I'm trying to keep in mind with my sales-letter. Of course I want to appeal to the truly overweight but I must also appeal to these sorts of super vanity types.