Marketing is the selling of a product or service, but with the use of advanced method. Marketing can use any number of techniques, from calling, subliminal messages, NLP, and more.
Marketing typically uses a group of people for feed back on a product. This is called a focus group. Focus groups are chosen from a segment of the population. A segment is a group of people that share a place in society, like poor, urban, suburban, rich, etc.
Repeat customers and good image are very important to profit. There are warm calls and cold calls. Cold calls are randomly chosen, warm calls are people who are known or already are known to like a similar product.
Percentage of success based on color and wording in each demographic is usually recorded and kept to work from for future marketing.
Key words are often included in ads that cause a person to have interest or excite them. Images also. Sometimes things are included for being something that the audience knows. Demographics are often different in what can sell a product.