You can sell your products on Amazon, it is very easy process. You have to just visit for Fulfilled By Amazon and fill the registration form it is as simple as any email account creation form. You have to list your product on Amazon FBA is very simple processes.
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I think amazon is just for companies, but you can use Ebay. You make an account and then make an ad. I personally have never sold anything, but my dad has. And they bid on Ebay, so people pay more for the product.
No, you can sell items. I do not have an amazon account but you have to go on amazons "marketplace", list your item, describe it, and wait for a buyer. Sorry about the inadequate detail