When I use to sell products I also never sold products that I knew were junk, and the reason was because I knew if a customer bought the product it would hurt me later. If you sell products that you know are junk the customer may not return to buy anything else from you, and if you offering a guarantee you will only loose money when the product is returned.
My mom bought one of those hand held sewing devices (I can't remember the name of it), and it was a plastic piece of junk! She tried to return it to the company she bought it from, because they offered a guarantee, and they wouldn't take it back -- they told her she was stuck with it, and she told them their product was junk. The company she bought the product from was not a distributor, she bought it directly from the manufactuer.
I think many of those "as seen on TV" products are junk, but I have read about a few good ones. My advice is before you buy one of those products search the Internet for consumer reviews. I believe Readers Digest still does reviews of the products, and you can always check Amazon and Epinions as well. If you can't find a review on the product post in the forums to see if anyone has purchased it, and make sure to ask if the product done what they said it would do.
