I understand that. However, legitimizing any aspect of CAK's actions on this point, or debating the minutiae of any perceived technical allowance of media mail for comic sales, serve only to dilute the discussion of CAK's unreasonable delay in shipping and his subsequent weakest of weak sauce attempts to rectify that already unreasonable delay by shipping the item in the slowest, cheapest, least secure manner.
CAK's actions are the forest. Seeking to discuss the quality of the length of a branch on one of the trees distracts from the view in totality.
It's very possible to debate another point without allowing it to dilute the main point, which is that customer service is very important and the bigger the screw up the greater the customer service effort should be.
But let's be realistic here. How much effort is it to get a fricking book in the mail. Seriously.