For several months I was an audio engineer for a company which did the in-house commercials for supermarkets. The business the company was in was to sell national spots, but my job was to record all the free spots they gave to the supermarkets in order to get the supermarkets to play the company's ads.
So I did all the "We have a baked beans special in aisle 12 here at Food Emporium*" ads. I would do upwards of a hundred 15 to 60-second spots in a day.
But I also was given the task of taking certain national spots and essentially "mastering" them for noisy supermarkets. The term John Cheary used for that task was "make this sound terrible*".
And with the 1176 compressor and some broad sweeps of EQ I would do just that. But boy, I promise that after I smashed that signal you would be able to hear it everywhere over the crappy PA system in the grocery store.
Well for the last 20 years or so (about the same about of time as the existence of the CD but that's only a coincidence) we've been in a so-called "loudness war" where mastering engineers have been slamming the levels of records harder and harder until all albums sound like white noise. I've gone over this before but I'm thinking that I just don't care.
The only things which mastering engineers ever talk about which doesn't involve smashing the dynamics so that a record is "competitive in the marketplace" are the soundstage and how wide the stereo image is. And that is easily played with (primarily by using some M/S limiting but also occasionally some fun analog-ish EQ) in the mix.
And all this hemming and hawing I'm doing is just to say by golly, I'm just not going to do any sort of mastering other than mastering myself. So there.
*I still know the Food Emporium jingle. Be thankful that you do not.
**He may have said something more graphic. It was a long time ago.