Uploading a file to the base directory is only for people who sign up with the eBay affiliate program for their own website. But HubPages includes eBay in their Earnings Program now. So you don't need to sign up direct with eBay. You do the sign up process through your HubPages account under your Earnings tab. It's easy and quick. Just follow the help directions under that tab.
Soon Amazon will also be included in the HubPages Earnings Program.