Goodreads has a 5-star rating system. I find it pointless to give a book a less than 3-star rating. If you don’t like the book that much, why keep reading it? (Although I did give 1-star in a fit of pique to a SF novel a few years back, likely because acquaintances raved about it.)
If a book gets 3-stars that’s my way of saying it was okay, and I liked it enough to finish it. 4-stars mean I liked it enough to recommend. 5-stars mean it was great, and I hope to reread it some day.
But over Christmas I just finished reading Iain Banks’ A Song of Stone. It was so unenjoyable, but he’s a writer I like so much that I couldn’t drop the book.
So now 2-stars means this book stinks but I finished it out of brand loyalty.