"What is poison to one, is honey to another."

For a toothbrush I have used only once, its value to me is as if it were new, while to others, it is just a worthless piece of trash.

Survival of the Fittest Adaptation to the Environment

So, how do you rank the value of your toothbrush and mine based on their value?

Clearly, no ranking will be satisfactory.

Unlike ordinary standardized goods, the value of non-standardized long-tail products only has meaning in the context of a specific evaluator.

Therefore, to solve the problem of the diversity of value, we cannot use a single real number to represent value. Instead, we should use an n-dimensional real vector to represent value, where n represents each individual evaluator, with each person giving their own valuation.

However, traditional supply and demand theory can only provide a single real number representation of value. So, how can we accurately capture each person’s sincere evaluation of the product? Moreover, we need to take into account that some individuals may have the motivation to misreport their own valuation in a particular dimension.

"Birds of a Feather Flock Together"

In a society with sufficient social interaction, people with similar values will naturally form groups. However, the question is: how can we help people find others with similar values among strangers without wasting their energy in unnecessary social interactions?