Alan Levinovitz examines the history of the book blurb:

In 1936 George Orwell described them as "disgusting tripe," quoting a particularly odious example from the Sunday Times: "If you can read this book and not shriek with delight, your soul is dead." … When did this circus get started? It’s tempting to look back no further than the origins of the word "blurb," coined in 1906 by children’s book author and civil disobedient Gelett Burgess. But blurbs, like bullshit, existed long before the term coined to describe them ("bullshit," in case you were wondering, appeared in 1915).

What the future holds:

The blap is a glossy page covered in blurbs that immediately follows the front cover.

In deference to its importance, the width of the cover is usually reduced, tempting potential readers with a glimpse of the blap, and perhaps even accommodating a conveniently placed blurb that runs along the length of the book. The blover is essentially a blap on steroids, literally a second book cover, made from the same cardstock, that serves solely as a billboard for blurbs. Blovers are not yet widespread, but given the ubiquity of blaps it is only a matter of time.