There are five things that regularly happen in online auctions and
do nothing but annoy the potential customer of the seller. These
five things are:

1) Spam
2) Typos
3) Indirectness
4) Squabbling
5) Misrepresentation

These five things are common in auctions online and do little to
promote the seller, the auction house, or the industry's merits to
the customer. I will explain each of these and give tips on how an
auction seller can avoid making these mistakes.

Spam
Most people on the Internet know what SPAM or unsolicited email is.
Most also know that they don't like it. Many auction houses, such
as eBay, have specific rules regarding using email to contact
potential or past buyers about a seller's auctions and they have
steep consequences for breaking these rules. In general, if the
potential buyer hasn't asked to be alerted to your new auctions,
don't do so. There are a lot of ways to build a successful opt-in
list, and many buyers who are happy with your service are willing to
join such a list.

Typos
The next big pet peeve of the auction buyer is to see a post, email,
etc. with a lot of typos, incorrect grammar, and bad links or email
addresses. It pays for the seller to double-check everything they
post or email before sending it so as to catch these problems before
the customer sees them. Failure to do so will surely lead to lost
sales.

Indirectness
A seller who speaks indirectly or won't commit to answering a
question (or worse: dodges it altogether) will lose the trust of the
potential customer and therefore will lose the customer. A seller
should always do his or her best to be frank and up-front with
customers about products and services. If you don't know the
answer, find it and make sure you tell the customer.

Squabbling
The worst thing a seller can do to lose a customer is try to fight
with them. If a customer makes unreasonable demands, tell them that
they are being unreasonable and be professional about doing so.
Don't whine, complain, or make excuses. Be up-front and your
customers will respect you for it, even if they aren't happy.
Professionalism is a must when doing any kind of business.

Misrepresentation
The fastest way for a seller to get negative feedback or nasty email
comments (usually both) is to misrepresent their product - whether
intentional or not. Don't list something as "mint" if it has a
glaring scratch down the left side. Don't market it as "still in
manufacturer's packaging" if it's obviously been opened. Granted,
there will be buyers who will nit-pick over every detail to find a
complaint. By and large, though, most buyers will be happy to leave
you positive feedback if the item's description and the item they
receive are a good match.

Avoiding these pitfalls in selling at auction online will greatly
increase your returns both monetarily and in feedback. Good luck
and happy selling!

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Aaron Turpen is the proprieter of Aaronz WebWorkz, a full-service
provider of Web needs to small businesses. He publishes an online
auction-oriented newsletter every week, free of charge:
http://www.awwstore.com/signup2.html