I know I’ve often looked at the free sample of a book on Amazon only to find they only included the table of contents or even less. Always makes me wonder what they’re hiding. For non-fiction I could understand that, but for fiction, if the book’s well-paced, then in theory, you should be able to let people read even half the story. Those who like the story will still want to buy, those who don’t like it won’t buy anyway (and you haven’t lost anything), and you just might convince a few people who were on the fence. Since you’re delivering infinitely copiable digital goods, not brownie samples, you can give away a bigger piece for basically the same price, and you’re not wasting “material” on people who don’t buy. I’m sure you know of self-published authors who give the first ebook in their trilogy away free, openly stating that they hope people like it and will pay to read the next two books.
Since CoG stories usually start with building your character and introducing NPCs, the first few chapters might seem slow, and few of the decisions will pay off yet. I know for most CoG demos, I’ve come to the end of the free content and said, meh, maybe it gets more engrossing, but I haven’t seen anything that would make me pay to find out. It might be beneficial to “give” more of the book away, so readers have a chance to get invested in the characters and outcomes, and be more willing to pay to find out what happens next.
Or, that could backfire, and the complainers will react violently to having gotten so far into the story then be asked to pay (even though they were warned).
It does seem unfair that people who haven’t bought the full version as IAP can still leave a rating and review. Preventing that would require a big change in sales model, though.