Another key is to focus intently on servicing your auction customers. This service is far more important than in almost any other segment of your customer base. The auctions have the most intricate word of mouth system available. In addition to a customer being able to badmouth your business to his friends and family, he can post negative comments. Savvy bidders won't do business with vendors with poor ratings.
Many systems make it difficult, or even impossible, to remove a bad comment, even if it's untrue.
Keep in constant contact from the moment the auction closes, and follow-up for satisfaction. It will be appreciated. Remember to use a reserve price if you can't afford to give the product away for next to nothing. If your plan is just to get a potential customer list, and you can easily afford to buy the names at this price, go for it. Finally, don't be discouraged.