Each trade would have unique guarantees enabling buyers to purchase from any seller with total confidence. The system would be funded by a percentage cut of each transaction and would grow organically rather than being centrally planned. Individual sellers would set their own pricing formula and availability. To help, the system would collate and display patterns in pricing and demand in each sector. GEMs would not require its users to have a credit card, or even a bank account.
GEMs do however require a little help from government before it can start.
There are facilities which only governments control that could be used to underpin an electronic marketplace in which anyone of their citizens could sell anything. Someone who wants to sell their services as a tractor driver for instance might find a PIN number on their driving license that can be used for online proof that they have such a licence. The system issues a contract between each buyer and seller, this could be given specific legal status. Government announces it will award a concession on these benefits to whoever will build their country an electronic marketplace and install kiosks around the country so that this new way of selling is available to all. To merit this initial investment by private operators the concession will probably need to be for a period of around 15 years.