What is AIDA?

Legal Definition
AIDA is an acronym that stands for Awareness, Interest, Desire and Action. The AIDA model is widely used in marketing and advertising to describe the steps or stages that occur from the time when a consumer first becomes aware of a product or brand through to when the consumer trials a product or makes a purchase decision. Given that many consumers become aware of brands via advertising or marketing communications, the AIDA model helps to explain how an advertisement or marketing communications message engages and involves consumers in brand choice. In essence, the AIDA model proposes that advertising messages need to accomplish a number of tasks in order to move the consumer through a series of sequential steps from brand awareness through to action (purchase and consumption). The AIDA model is one of the longest serving models used in advertising, having been developed in the late nineteenth century. Since its first appearance in the marketing and advertising literature, the model has been modified and expanded to account for the advent of new advertising media and communications platforms. A number of modified alternative models are in current use.
-- Wikipedia