My website is an e-commerce based site and therefore has a few back-end duplicate content issues that im trying to fix. I have added the canonical tag to the majority of my back-end category pages which are the same/similar to the front end pages, my question is shall I optimize the back end pages in the hope they pass some form of link 'juice'? Or shall I leave them un-optimized as they currently are (so they don't rank against current pages?).
There is no direct link to the back-end category pages but these pages do contain links to back-end product pages if this has an effect? As ive heard that you shouldn't really link to pages that have used these tags.