In the normal distribution demand curve, the protruding part in the middle is the head, the relatively gentle part on both sides is called the tail, the most demand is concentrated in the head part, and the individual and small quantity demand is distributed in the tail part. The long tail effect means that adding up all the markets distributed in the tail department will form a market larger than the head market, emphasizing personalization and big market with small profits, that is, earning very little money per person, but making a lot of people's money.
According to the above definition, which of the following belongs to the long tail effect?
Many people don't know how to choose gifts. Xiao Ren has set up a website to select gifts according to the requirements of different customers, charging a service charge of 5 yuan per order. Six months later, the monthly income exceeded 100,000 yuan