Once someone's bought something from you on eBay, you suddenly have all sorts of details on them. In marketing terms, this information is gold dust. If someone's bought from you once before, then the chances are that at some point in the future they'll want to buy a similar item, and you can take advantage of this to market to them directly.

The simplest form of direct marketing is the email newsletterand it's one that is still oddly underused on eBay. Simply ask people who buy from you if they'd like to be added to your mailing list, and then send them a monthly update on your new items. You should also include some information you think might be useful to them, to give the email more value.

For example, here's a newsletter you might write if you were selling DVDs.

'Here are the dates for this month's new DVD releases:

[list of release dates]. If you want to pre-order anything on this list, just click here [your website/email] and let us know.

Meanwhile, we've got some great deals for you this month! [links to your best ebay auctions]

You are receiving this email because you signed up for my newsletter when you bought an item from me on eBay. To unsubscribe, hit reply and type 'remove'.'

Isn't that simple? As long as you can remember to do it once a month, people will come to like your information, and perhaps take a look at some of the things you're offering.

It's all about building up a customer relationship, and making the customer feel like you are providing them with some information they wouldn't otherwise have. Make your email a useful service to them, whether they buy anything from it or not.

Remember that it's not a newsletter without the news, and send out the best things you can think of: you might even try writing an article or two. Think of it as a free gift for your customers: the gift of useful information. Apart from anything else, it's quite fun to have your own newsletter.

If you sell items that a seller is likely to need more than one of, like auto parts for example, then you can even try highly targeted emails like this.

'I'm sending you this email because you bought a [item name] from me a while agoI hope you were happy with it. This is just to let you know that if you ever need another [item], I'm currently doing special offers on them. [link]'.

You would probably want to automate this, though, as it could quickly get tedious to do it manually.

Of course, that brings us on to our next subject: eBay stores. eBay stores offer you an easier way to sell your items than having to list them every time on eBay, and they have built-in facilities for targeted direct marketing. You can read all about it in the next email.