When I'm not writing books and being denied that I exist by Amazon (though since they probably worship the monkey-god I can't really complain too much) I'm curating content over at the booklight.
The most recent review was my own, which was Sliced Americana which is a Science Fiction book written by 8kun's Jim Watkins. I let Mr. Watkins know about the review, in hopes that it might be used to help raise funds for 8kun as it has shown a continuous record of advancing free speech. (Despite a lot of content being reprehensible rubbish. Freedom with garbage is better than no freedom and no garbage.) He pinned the review for a couple of days to his Twitter account, and the views of the post I think were somewhere around 3,000.
I can safely say that that exposure did not drive any sales of my book, although Watkins tacitly endorsed it. Hopefully people bought some copies of his, however.
The point in either case isn't selling books. The point is about supporting what you believe in. Most of us are buying things from companies that actively hate us. We have to exert an effort to support places and ideas that don't hate us. Buying from adversaries has been "made easy" because well, let's face it, Satan makes accessing death easier than going for anything more rewarding.
Stacker.news offers the potential to support Indie Artists like me, who Amazon denies exist. (I hate to think about any more spiritual claims they might hold) It is very easy to support Amazon. They own half of the literature in the natural world. It is not so easy to support author X, since first you have to know they exist, and want to support them or their work. It also makes it possibly to support the Watkinses of the world who have some high ideals which jar against those that do not though they find themselves in the same bedroom.