Who are you trying to kid?
Let me be honest here. If I see a self-published book with nothing but 4- and 5-star ratings, what's my reaction? Do I think, "wow, this must be an utterly amazing book and I must read it at once?"
No, I don't.
I immediately assume it's rigged and all those reviews are probably from family and friends, or they're paid reviews, or they're reviews swapped with other authors. I simply do not believe for a minute that nobody has anything bad to say about a book and that it's absolutely perfect. My reaction isn't to buy the book - quite the opposite! I assume it's probably mediocre and not worth my time.
I would far rather see a spread of honest reviews, telling me what's good and bad about a book. Sure, some people won't like it. That's fine. Some people don't like War and Peace. Some people don't like the Da Vinci Code. Some people don't like Tom Clancy's Op-Center. That doesn't stop people reading them. Frankly, if you're not getting negative reviews, you should be surprised. Nobody is exempt from criticism, and if you're not getting them, then you're probably surrounded by yes-men.
From a 3-star review of War and Peace on Amazon:
It's... overwritten, wordy,redundant, repetitious, chronologically clumsy, and loaded with structural defects, writer's errors and digressions. Tolstoy himself called it "verbose", and said it had too much that was "superfluous". I agree with Tolstoy.
What do these ratings mean anyhow?
As far as I'm concerned, ratings aren't objective. They're subjective. They tell you what I thought of the book, and I like to use the whole scale. An average book gets a 3 - and remember that average doesn't mean it was bad. It meant that I liked it. Something I really liked gets a 4, and a 5-star rating is reserved for those very rare books that absolutely blow my mind. On the other end, a 2 was disappointing, and a 1 is something I just couldn't finish or is really badly written.
Sadly, many authors don't see it that way. One author to whom I gave a 4-star rating asked why I'd "knocked a star off", even though I'd praised the book and said how much I liked it. They seem to see a 5-star rating as the default, and anything less is a failure. That, to me, totally negates the point of the rating system - how can I, or a potential customer, distinguish between a good book, a really good book, and an exceptional book if they all get 5 stars?
A 4-star or 5-star rating should be something to covet, not something to expect, and I actually think it does authors a disservice if they're led to believe that everything they write is as good as - or better than - the very best literature humanity has produced. If your YA fantasy really deserves that 4.5 average, why isn't it outselling Harry Potter with its mere 4.3 average? Is your 4.8-rated thriller really better than the 4.6-rated Day of the Jackal? Is your 5-star erotic short story a classic to overshadow the 4-star Delta of Venus? If you really want to know, then give it to a thousand people and they'll tell you what they really think - and if you can maintain that high rating, then congratulations, you're officially one of the greats! But don't be surprised if most of them aren't as awestruck by your masterpiece as your first few fans.
Who are ratings for?
The thing is, ratings aren't just for your benefit. They're for mine. Amazon recommend me books according to what I like, so if I tell them I didn't like a book, they won't recommend me other books like it. That 1-star review doesn't necessarily mean "this is a bad book," it means "it wasn't to my taste."
They're for my friends too. If Dave sees me give a book a 1-star rating, he can legitimately conclude he won't like it either. If he sees me give it a 4 or 5, he's likely to give it a try.
Tailored ratings systems
What I'd really like to see is a more sophisticated system like Netflix which shows me both the average rating and an assessment of how it fits to my personal tastes. When I look at a movie on Netflix, it's not unusual for it to get a high average review but a low score for me - or vice versa. The latest teen comedy may score really highly with some people, but Netflix is smart enough to figure out that people who like the same movies as me don't think much of it, and it tells me I probably won't like it. On the other hand, most people don't like silent German movies, but it knows that I do, and gives me a rating based on that knowledge.
Netflix spent a fortune developing that algorithm and saw a huge increase in viewer satisfaction. If Amazon and the booksellers could do the same, I'm sure it would pay dividends in terms of sales. Authors would benefit too: if you do a better job of targeting your book to readers, you'll get more satisfied readers.
It comes down to this. When I read the reviews of books, I want to know whether I will like it, taking into account my tastes. If I can be sure that a 4-star book is probably excellent, I'm more likely to buy it than if 4-stars is considered a low rating.
So I'm sorry, authors, but I'll keep on dishing out the 1s and 2s.