Final answer:
The term that describes when the public is convinced of the value of a campaign's appeals and 'buys into' the message is called bandwagon effect.
Step-by-step explanation:
In the context of campaigns and persuasion, the term that describes when the public is convinced of the value of a campaign's appeals and 'buys into' the message is called bandwagon effect. The bandwagon effect refers to the tendency for people to follow the actions or beliefs of others simply because they see others doing the same thing. Advertisers often use the bandwagon fallacy to create the impression that everyone is buying a product, in order to persuade others to do the same.