Sales promotion consists of all promotional activities other than advertising, personal selling and publicity, which are used to encourage the buyers to make immediate purchase of a product or to boost its sale.

According to A.H.R. Delens : 

sales promotion means those steps that are taken for the purpose of obtaining an increased sales. Often, this term refers specially to selling efforts, that are designed to supplement personal selling and advertising, and by coordinating, helps them to become more effective.

According to Robert C and Scott A : 

sales promotion consists of a diverse collection of incentive tools, mostly short-term, designed to stimulate quicker and/or greater purchase of particular product/services by the consumers from the traders. Advertisement is different from sales promotion. Although, both are used for increasing the sales of the product but both of these are different in nature.

Points of difference are explained below :