Years ago, I started releasing one of my old novels, "The Star Slavers," on my website. It got some attention as it was slowly released in segments, and those who enjoy a good, traditional space opera will find it appealing.
When I shopped this around to publishers many years ago, the response I got back was simply, "It's been done before." A couple of editors really enjoyed the story, but they didn't think it was different enough to stand out. Every professional who sampled it thought the ideas presented weren't original enough, and that is fairly typical of the publishing market today. They are not after fun stories. They want something weird or different, anything that is "new." If you write entertaining pulp, there just aren't many markets for you anymore.
So, after years of getting the same answer from big and small publishers, I decided to release the book on my own website, rather than let it sit in a drawer forever. It's all there, except for the final chapter. Start at the beginning and see what you think. If enough people like it, maybe I'll release the conclusion.