Imagine that you are back into dark ages in a still undeveloped third-world. What is the only asset you have in a primitive society? Your name and reputation.
Most of poor and under-developed communities are (naturally) socially-oriented, and the name, reputation and so-called "lose of one's face" are of paramount importance.
So, this is how to survive in a primitive society - have a decent reputation of (really) being good at something. Just this -know your shit and be known. Usually, it happens automatically.
The Law Of Karma
The ancient "law" states, that you are the sum-total of all your actions (or deeds). Well, reputation is just a derivative of all your publicly known social actions, if you wish (while what you are is just a sum-total of all your thoughts and actions).
This law is confirmed by millennia, there is literally nothing to talk about.
There are no shortage of online sweatshops which squeeze themselves in the middle between a serviceman and its actual customers. Everyone know Upwork or its clones.
Another kind of sweatshops are reputation-based QA sites, such as StackExchange, where you get points for answering other people questions.
Nowadays almost every public forum or a non-anonymous discussion board has so-called "karma-points" which measure your reputation (according to a particular culture of the place).