Answer: It is an example of a direct, disguised observation.
Direct observation, also called an observational study, is a form collecting evaluative information whereby the researcher watches the subject in his or her environment. Direct observation is sometimes used when other data collection processes such as questionnaires, surveys, etc., are not effective. Direct observation is also used when the goal is to take note of an ongoing behavior process, situation or event, or when there are outcomes that the researcher can readily see.
Direct observation can either be overt, that is, when the subject being researched on knows the purpose of the research, or covert, that is, when the subject is not aware of the researcher's presence or purpose of the observation.
The answer is product popularity product popularity appeal refers to an marketing tactics that relied on the number of customer base in order to create a perception of good quality product. In general, people who see a product with large customer base will believe that "That product must be good, since many people use and trust the product"