Or so says one of Australia's leading poets, Les Murray.
In an interview with Sydney Morning Herald, he says that are, "all hyperbole and hype, a publishers' bad habit. Read the contents of the damned book."
He said this after a publisher asked for his blurb for another poet's upcoming book. His response was to ask the publisher to publish his wife's book in return.
Unfortunately, the article did not state what the publisher's response to that was!
Personally, I think blurbs don't do any harm, even if I know that the author giving the blurb was just doing it as a gesture for a friend, and probably didn't even read the book.
If I wanted to know whether a book was good or not, well, that's what we have book reviews for. Not that hard to get on the interwebs and google for one.