The primary advantage of such a method is that conditions are laid out in advance, and transactions can proceed with no further permission or authorization from any participant.
[1] Samuelson wrote that "the price mechanism, working through supply and demand in competitive markets, operates to (simultaneously) answer the three fundamental problems of economic organization in our mixed private enterprise system..."[2] and establish an equilibrium system of prices and production.
Market constitute an integral part of the price mechanism A market means a system or a set-up in which the buyers and sellers of the commodity are able to interact and communicate with each other and strike a deal, i.e., price and the quantity to be bought and sold.
If the terms "pay" and "sell" are understood very generally, then, a very broad range of applications and different market systems can be enabled this way.
Internet dating for instance could be based on offers to talk for a period of time, accepted by those who are compensated not in money but in additional credits to keep using the system.
Though there are many concerns about liquidating any given transaction, even in a conventional market, there are ideologies which hold that the risks are outweighed by the efficient rendezvous.
Somewhat more controversially, the approach was applied even earlier to sulfur dioxide emissions in the United States, and was quite successful in reducing overall smog output there.
In most applications of such methods, however, the comprehensive outcome of the transaction is not so easily measured or universally agreed.