Analyze Your Auctions/eBay
Besides analyzing your sales data, it is wise to analyze eBay and other sellers auctions. It is the best way to judge how well you are doing. For instance, if you are only selling 5 of Product "A", while your competitor is selling 10 of virtually the same product using the same advertising placement and at the same price, this indicates that you are not doing as good as you could be doing.. Generally, if something like this is occuring to me, I will ask myself, "What is better about their sales technique?" I will look at their ad description, their picture icons showing in the search results, their titles, their categories, etc. After doing this for a few months, it will get easier and easier to analyze other's auctions and sales.
Knowing how to use eBay to your advantage as a seller is crucial also. Many do not know how to do this. Here is are a couple simple tips. First, look at your competitors "Page View Counter Graphic" near the bottom of their auction(s). Often, it will tell you how many people are coming to their page. Then, divide it by the amount of days their auction has been up. Look at your "Page View Counter Graphic" for your related product and also divide by the number of days it has been up. If they are not even remotely similar, yours being a lot lower, they know something you do not. For instance, maybe they have a better keyword usage in their title or maybe they have a better category they are listing in. Another little tip is to do a search related to your product and then click the check box for "Completed Listings" underneath the "Search Options" Subtitle on the left side menu. Then, click "Show Items" Button just below it. This will show all the completed listings for the information you are searching, which is FAR more relevant than the current auctions that are up. This is a way for you to analyze other people's auctions that have ended. Not all the details will be shown, but enough for you to make projections and analysis.