Until you figure out the ins and outs of getting people to buy your items, you will not be making money. As you study the system, you will also learn that the site adds favorable weight to stores that have sold more items. At the same time, eBay will do everything it can to get paid their fees, irregardless of who the seller is. This includes making it seem like a good idea to let them take the money to cover insertion fees directly from your Paypal account.
In many cases, you may well find yourself thinking that you have been double billed. Once your item fails to sell, it is extremely easy to think it can not hurt to re-list "for free". Unfortunately, you only get the second listing for free if the item actually sells. Then you will pay a commission on the sale. If it does not sell, you get billed for two insertion fees. The bottom line is this. One way or another, eBay gets paid for every single listing. You can easily wind up with over $ 100.00 worth of insertion fees and not one single sale to show for it.
If you watch a specific set of listings, you will get some idea of the real percentage of items that do not sell. This results in lost money to the owner of the store or the product. By gauging this percentage, you will be able to get some idea of how useful eBay will be when it comes to selling your product. You may well find that as low as the insertion fees are, it is really just throwing money away that could be spent on better opportunities.