There’s an art to book blurbing, as anyone who’s tried to write one can tell you. Over at the Kenyon Review, Jake Adam York takes a stab at classifying them. For example, there’s the “Lavish” type:
The genre of the recommendation letter, a friend once observed, is hyperbole. Everything has to be stated in [...]

The always-fascinating TYWKIWDBI points us to the origin of the blurb. According to Wikipedia,

The word blurb originated in 1907. American humorist Gelett Burgess’s short 1906 book Are You a Bromide? was presented in a limited edition to an annual trade association dinner. The custom at such events was to have a dust jacket promoting [...]

We all know you shouldn’t judge a book by its cover. But now, with Ward Six’s handy Literary Blurb Translation Guide, you can judge it quickly and easily by the blurbs on that cover. Some examples:

“luminous prose” = too many goddam words
“unflinching artistry” = lots of boobs and stabbing
“taut” = limited vocabulary
“incredible range and [...]