Is it possible to use the Ebay API to create a solution where sellers can go, enter their listing's 'item number' and a 'keyword' to find out the ranking of the listing for that keyword? See this image to understand what I mean - http://www.shareimages.com/images/pics/0/0/3/77345-pJOZl5mek6Wpk5.W-img_19032014_160909.png