Own custom ads with corona ads

Hi, I would like to use corona ads in my app but I would like to set it up so I can sell my own advertising space and not use the classic network. Is this possible at all? Do I have access to any analytics this way? I know admob has one solution for this scenario. Also how is it possible to have custom banner sizes in this case? If any or all of this is possible I would greatly appreciate a tutorial on how to…thanks