how many people are selling products on ebay?

I sell on Ebay and so far things are doing good. I try to avoid posting stuff that would make me pay additional seller's fee. So far, I've sold several things on Ebay and in a couple of weeks, I plan to really make things work. I have not opened a store. I'm not sure if it costs more or what. Just recently I got a paypal account so that has opened a bigger door for me in selling. I'm still new at the selling thing but I think I'll get better as time goes by.