When setting up a product for an ebay listing, have a panel/section that is an AJAX call that provides you the suggested categories for the listing using the GetSuggestedCategories API call. https://developer.ebay.com/devzone/xml/docs/Reference/ebay/GetSuggestedCategories.html As an idea, it could use the text provided in the product title/ebay title fields as the query string, and then display the five best matches. As a another function, then having you select one of the suggested categories as the one to list in for the wordpress item.