There was a "generic" product craze in the early 1980s. Black-on-white labels covered products from soap to beer. In 1981, I remember seeing generic books appear in the check-out counter racks of grocery stores. They were a buck-and-a-half, less than sixty pages, covered four genres: Mystery; Romance; Science Fiction; Western, and promised a story with exactly the conventions you would expect from their respective genres. I read the Western and the Science Fiction volumes. They were definitely done tongue-in-cheek, but were good enough that I was disappointed that only the four were published.
Recently, I got on a nostalgia kick and tracked them down. I had to use the internet to do so; in all the years since 1981, I never, not once, saw any of them show up in used bookstores. They had always been a bit of a mystery to me, but the internet being the wonder of our age, I was able to run down some info about them. This blog, especially the comments section, is one of the best sources of information I've seen about them.