It is very important that you know who your seller is on eBay.  This is not mean that you need to know the person individually but simply that you have been able to determine by reviewing their feedback that the number of transactions successfully completed by the seller is sufficient to justify your confidence in the person or company as a seller.  As a general rule of thumb most people tend to avoid sellers with feedbacks which are extremely low for instance under 10 or those whose feedback rating is a lower percentage.  As a general rule if a person has a seat back rating of over a hundred with a positive rating of over 98% chances are very good that you will have a successful transaction take place.