Does anyone know how important it is to have the correct UPC when making detailed product creation pages on Amazon with the Pro Merchant account? I have a couple of products that I want to put on Amazon that dont have UPC codes. Will they catch on, and if they do what are the consequences? I know I should go to egay, but I am not to that goal yet. Amazon support said that I must have the UPC for the product to post on Amazon, or else it is not allowed? I will give thanks to anyone who helps.