Demographic information includes: age, gender, regional distribution, preference, economic income, cultural characteristics, etc.
Our domestic market is a very interesting example. If you are a company that sells sports shoes. You can find that many 40-50-year-old peasant brothers and their children can't tell the difference between Adidas and Adi King. You can imitate Adi King. It can also be found that elites in many big cities frequently go abroad or even emigrate, and it is very embarrassing not to play high technology or online data.
In short, if we want to dig some money from a huge market, we must study the characteristics of people in the market: how many doctors, how many graduate students, how many undergraduates and how many high school students. Then you have to find out whether you want to earn money from people with high education or people with low education. As I said before, if you sell Adi Wang to undergraduate and graduate students, I'm afraid it's a little difficult!