sales promotion vs promotion

sales promotion and promotion both are nouns.

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

As nouns, promotion is a hypernym of sales promotion; that is, promotion is a word with a broader meaning than sales promotion:

sales promotion: promotion that supplements or coordinates advertising
promotion: a message issued in behalf of some product or cause or idea or person or institution

Other hypernyms of sales promotion include packaging, promo, promotional material, publicity.

sales promotion (noun)	promotion (noun)
promotion that supplements or coordinates advertising	act of raising in rank or position
	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