1: the act or fact of being raised in position or rank : preferment
2: the act of furthering the growth or development of something; especially : the furtherance of the acceptance and sale of merchandise through advertising, publicity, or discounting
1 a: the act or process of selling or purchasing in a market b: the process or technique of promoting, selling, and distributing a product or service
2: an aggregate of functions involved in moving goods from producer to consumer
1: to make something known to : notify
2 a: to make publicly and generally known b: to announce publicly especially by a printed notice or a broadcast c: to call public attention to especially by emphasizing desirable qualities so as to arouse a desire to buy or patronize : promote
It would seem that these terms, (promotion, marketing, and advertise) are essentially the same thing.