One of the things that can be most bewildering to sellers is the case of the negative feedback repeat buyer. You've listed some items for sale. Someone won one of your items, and you delivered it in what you thought was good faith.
Fine. Those things are an unavoidable part of doing business at times, and though you were frustrated (maybe even infuriated), you were calm and professional, did your best to provide good customer service despite the circumstances, and you coped. You were ready to move on to other buyers or transactions.
Only now, that same person has bought another one of your items (maybe even a second of the same item) and you're expected to do business with them all over again!
What is going on here? Should you do it? What happens if you don't do it? How can you avoid having to deal with this problem all over again, a second time?
What's Going On?
There are any number of reasons why someone might initiate a second transaction with you after the first transaction went wrong. Some of them are innocent, and some of them are not. First, let's look at some perfectly good reasons:
They were being objective, not petty. Maybe the first item arrived damaged and they attributed this result to poor packaging practices. Maybe it took too long to arrive and they put this down to delays by you. Maybe the first item arrived DOA and they were in a hurry to use it. There are people out there that are simply rational and objective, not personal, in the way that they approach commerce and eBay feedback. They felt that the previous transaction was a bad one, and rated it that way because they're "just the facts" kinds of people. That doesn't mean that they've made any assumptions about the next transaction with you. These kinds of buyers are just as likely to leave you a positive the next time around if everything goes well (and believe it or not, these kinds of people do exist and aren't even that uncommon).
They jumped the gun. Some people, particularly those that are new to eBay, have a fuzzy idea of how eBay cultue and the feedback system traditionally work. They may have have been only slightly dissatisfied or in need of customer service, but imagined that they needed to leave a negative before contacting you or eBay in order to "justify" their claim.
They want you to improve. In some cases, a repeat buy can be evidence that you've got a great product at a great pricethat you essentially have no real competition on eBay. In these cases, people may have been dissatisfied with their first purchase but are willing to try again because the value that you seem to offer is very high; perhaps there's no one else to buy from, or buying from someone else would mean paying much, much higher prices. They're unsatisfied with their first transaction but are hopeful about another transaction with you because they really do want more of your item(s) at your price(s). This case is a good opportunity for you to make another sale and potentially many more, if you think you can fix whatever went wrong the first time. The buyer is (hoping to be) relying on you. That's not a bad place to be if you think about it.
It was a mistake. It's always possible that the buyer simply didn't click the right button (a common reason for accidental negatives) or didn't understand the meanings number scale of the detailed seller ratings system (a common reason for two- and three-star ratings). In this case, they may not have intended to rate the transaction that negatively at all, or may have intended only to rate it slightly negatively, not realizing that they were doing something drastic.
They don't realize it's you. Believe it or not, not all buyers on eBay pay meticulous attention to the sellers from whom they buy. Many eBay shoppers are just like shoppers at other ecommerce sites; they're focused on the product and the price and may only be vaguely aware (or even unaware) of the fact that individual sellers are involved. Someone that buys and negs, then comes back two weeks later and buys again may not even realize that they're dealing with a person, much less the same person that they were so dissatisfied with just a few days earlier.
Of course, there are also less innocent reasons for leaving a negative and then buying again:
The buyer is a competitor or someone else trying to harm you. Buyers like this buy multiple items to get the chance to leave multiple negatives, perhaps in a short period of time. This can be a tactic to put a competitor out of business or knock a competitor off of eBay.
The buyer is so angry about the first transaction that they want revenge. Some buyers can be so angry about the first gone-wrong transaction that they then "take it out" on the seller, ending many of their other listings without paying for them, just to cause the seller trouble.
The buyer is trying to con you. Sometimes buyers use negative results as leverage to get better deals. Having already negged once (perhaps insincerely) to drive the point home, you may hear from this kind of buyer either before or after payment the second time around as they demand more from you to "avoid" another negative. They may ask for a reduction in price, for the second item as a freebie, or for additional accessories, perks, or services to be thrown into the mix "if you want" to escape unscathed.
This is all well and good, but having a theory for why someone may be buying from you again after being unsatisfied the first time around doesn't necessarily tell you what you should do next. Read on for some thinking points to help you to decide how to proceed.