promotion vs promo

promotion and promo both are nouns.

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

As nouns, promotion and promo are synonyms defined as:

promotion and promo: a message issued in behalf of some product or cause or idea or person or institution

Other synonyms of promotion include packaging, promotional material, publicity.

promotion (noun)	promo (noun)
act of raising in rank or position	a message issued in behalf of some product or cause or idea or person or institution
the advancement of some enterprise
a message issued in behalf of some product or cause or idea or person or institution
encouragement of the progress or growth or acceptance of something