This economic principle is called price discrimination. Price discrimination is essentially a kind of price difference, which usually refers to the fact that suppliers of goods or services implement different sales prices or charging standards among recipients when they provide goods or services of the same grade and quality to different recipients.

Price discrimination benefits the seller of the product as much as possible, because through price discrimination, the consumer surplus originally belonging to the buyer of the product is also transferred to the seller. However, according to the analysis of economists, price discrimination is economic and effective, that is to say, price discrimination conforms to the Pareto standard, and the maximum income obtained by the seller through price discrimination is equal to the maximum value of social welfare.

There are many people on weekends, and you can sell a lot without promotion. But the working days are different.