RANT ALERT/WARNING. If you don't want to waste time seeing me rant here, move along 
I suppose some of this rant could be aimed at the U.S. Postal Service as it is their media mail service level that is the target of my ire, but quite honestly the don't advertise that service as one which is fast. It's the fairly cheap service for delivering objects like books from one point to another and they pretty much warn you in advance that it make take 3 - 4 weeks for an object shipped media mail to arrive at it's destination.
So, knowing that the U.S. Postal Service isn't advertising that service level as something that it isn't, I really don't think they deserve to be the target of the rant. Which brings me back to the real culprit here -- Amazon.com -- for their stupid policy that designates 'standard shipping' as 'media mail' for books and DVDs (and video games) when someone like me is selling such objects, either used or new. And oh, yeah, by the way, also applies when buying an object from someone that is too cheap/lazy to upgrade the shipping to first class mail.
Huh?, I said too cheap/lazy? Why wouldn't it just be too cheap and why does lazy apply? Because many times the costs for shipping first class mail are *lower* than the costs for shipping media mail, with the big difference being that items shipped first class will arrive at their destination within 3 - 7 days at worst, while the media mail shipping may not get items to their destination for the better part of a month.
I wish that Amazon would revisit their shipping policies and make sellers of single package DVDs ship first class, and only support using media mail for books and heavy objects where there would be a price difference that makes using the much slower shipping worth the effort. If they'd do that, then everyone would win. Buyers would get items quicker, sellers wouldn't have to worry about impatient buyers that report not receiving packages because they haven't waited the 3 - 4 weeks that it might take to receive the package.
At a minimum, I believe that Amazon should go out of their way to REMIND buyers that standard shipping is MEDIA MAIL and that delivery may take 3 - 4 weeks so buyers should either be patient or make an informed decision to pass on upgrading to first class or priority shipping. At least if they did that the buyers couldn't berate the sellers that are meeting their obligations.