The concept of promotional effectiveness encompasses the ability to assess the performance and profitability of a promotional initiative. This assessment can vary in complexity depending on the nature of the promotion and the sector of activity involved. It goes far beyond a simple comparison of investment versus return. In the consumer goods and retail sectors, measuring this effectiveness proves particularly challenging. Generally, this analysis is based on consumer panel data and may require specialized studies or dedicated services provided by these panels.

Evaluating promotional effectiveness in mass retail takes into account various elements such as sales over the period, new customer acquisition, impact on existing products, changes in consumer behavior, interactions between different products, negative effects of substitution or competition, impact on brand perception (which can lead to devaluation), as well as the influence of other marketing and advertising activities.

A specific field is dedicated to the study and measurement of promotional effectiveness. Through clear and academic webinars, the different stages and components of this assessment are presented in detail.