Answer:
source credibility.
Step-by-step explanation:
The factor that contributed to the increase in product sales was the source credibility, which occurs when there is a strong positive appeal from the communicator of a message by the receiver, which in the case of a marketing advertisement, for example, leads to success for a company, as was the case mentioned in the question above, where a celebrity was used to communicate an advertising message that was strongly accepted by the potential public of the brand, which resulted in tripling sales of the product.
It is important to note that source credibility occurs when there is some relationship between the communicator and what is being communicated, such as the football player who promoted the new protein shake during the superbowl. Thus, there is a relationship between the player's characteristics and the product, broadcast in the ideal place and time where the potential consumers of that product are.