blurb vs promo

blurb and promo both are nouns.

Word	Noun	Adjective	Verb	Adverb
blurb	Yes	No	No	No
promo	Yes	No	No	No

As nouns, promo is a hypernym of blurb; that is, promo is a word with a broader meaning than blurb:

blurb: a promotional statement (as found on the dust jackets of books)
promo: a message issued in behalf of some product or cause or idea or person or institution

Other hypernyms of blurb include packaging, promotion, promotional material, publicity.

blurb (noun)	promo (noun)
a promotional statement (as found on the dust jackets of books)	a message issued in behalf of some product or cause or idea or person or institution