An E-bay business is a service oriented business but quite different in the fact that you never see the face of your client. It takes lots of sacrificed Hours,Days and Years to build a business on E-Bay just like any other business. Some times you can have over 1,000 items in inventory for sale and not have a sale for days. My first few years were spent finding my niche in ebay and I believe ti is books written in Spanish. My surroundings kind of dictated what I would be selling and why. Learning what you want to be your niche is sometimes a long process, but eventually pays off. Take a look at where you live and what is very common ther that you rarely find anyplace else. and that would be a good start. When you do start listing kind of do a variety of listings for example maybe a few things in household items, and maybe a few things in clothing and so on. Answer your  e-mails promtly because questions can significantly add to your sales. basically you can sell anything on e-bay but you have to have the service and the friendliness with the shoppers to get good feedback and to keep them coming back for more.