In the '70's and '80's when records were pressed in the millions, quality control sometimes took a left turn.
Here are some examples.
The Cry of Love - the first and one of the best posthumous Jimi Hendrix albums. It was a big seller. Take a look at the upper left.
You'll notice the writing on the spine is way off-center. This renders the side when filing away to look like this:
When going to the local record emporium to pick out the latest million seller, checking the side was always an important part of selecting a copy. I remember going through 25 or so of one particular title to find none that were 'good on the side.' A visit to another store got me what I needed.
Sides can be overlooked when a bargain is at hand or something sticks out in the used bin.
See below for a small section of my collection which features many 'good on the side' titles.