Is blurb a word in the Scrabble Dictionary

Yes, blurb is playable

...and is worth 13 points.

Found in the following dictionaries

Enable (Words with friends)
SOWPODS (Collins Scrabble Words)
OTCWL2014 (NASPA Word List 2014)
TWL06 (NASPA List 2006)

"Blurb" Definition

noun

A brief publicity notice, as on a book jacket.
A short publicity notice (as on a book jacket).
A short description of a book, film, or other product written for promotional purposes.

verb

To describe or praise in a blurb.
Write or contribute a blurb for (a book, film, or other product):.