I have removed ads wherever possible and have also removed back-covers. A few books had back-up features and so I only took the Crisis relevant texts to conserve space. I saved my cull pile and ended up with about two-three extra volumes worth of material from just adds alone. But given that I am pushing 200+ books. I am not too surprised by this. I have all the issues save for Christmas with the Super Heroes #2 which has the ghost of the pre-crisis Supergirl in it. Fortunately, I have found most of my issues in town at the local shops. I may have to track a few down online.