I'm talking here about the little potted review of the book that is usually on the back cover for paperbacks and inside the front cover on hardbacks.
Clearly this is one of the most important marketing tools for the publisher; a description of the book to draw the casual browser in and decide to spend their hard earned cash monies on the product.
I feel these tend to give far too much of the story away. So much so that I don't read any of the blurb for books and authors I know I will like. I much prefer to read the story and experience the reveals, the characters and the twists as the author wrote them. So many times a vital plot point that essentially ruins at least one of the story threads (in terms of suspense and drama) it given away by the potted review. The worst examples I have seen give a basic plot outline up to as much as three quarters of the way through the book, or reveals that a key character dies about half way through.
So why is this the case? Is it possible to write something that is interesting enough to attract the casual browser and give them enough information to tell if they are likely to enjoy the book? When I write reviews I try my hardest not to fall into this trap; I try not to give any plot details away that I can help (or that aren't going to be obvious withing the first chapter or so anyway).
One example of this was when reviewing <i>Prince of Fools</i> by Mark Lawrence. The core of the book is a 'buddy buddy' story of two protagonists - the feckless Prince Jalan and the powerful and driven warrior Snorri Snagason. The thing is I found this pairing a real surprise - especially given Snorri's first appearance is essentially as an extra, then Jalan uses him in the fighting pits in a bid to clear his gambling debts. The way they are eventually forced to work together was a real joy to read as it unfolded on the page and I would have hated that to have been ruined by knowing ahead of time who Jalan's companion was. So my review simply does not mention Snorri by name, keeping the surprise for other readers to discover for themselves (of course it's ruined now if they've read this!)
And indeed the write of the 'blurb' for <i>Prince Of Fools</i> seems to agree on this, and it's a fine example of how it should be done... no specifics beyond those that are immediately obvious. Snorri is referred to as a 'fierce Norseman' and not named and although they are described as being magically entangled it's really not clear what that means.
Now compare to the text for <i>The Bootlegger</i> by Clive Cussler and Justin Scott. Here the villains are explicitly described as "Bolshevik assassins and saboteurs", a fact that takes some time to play out fully in the book and is probably not fully realised until a good half way through the book as his motives are kept deliberately obscure.
But this needs to be tempered by the need to sell the book, to give enough details that someone might decide to pick <i>that</i> book instead of moving onto the next. It's got to be tricky to get this right but I'm sure a balance could be found.
So, writers of 'blurb' whoever you are, think about what you are giving away from the story and try to be specifically general in describing the content.