Many transactions are made on line rather than in shops these days. Auction sites often cater for small businesses, and these businesses are just as in need of protection from banks and multinationals as high street shops. Some sites are so big and multy purpose that it is hard to have an influence, but others serve a community of people with a common interest. A complimentary currency would aid traders on such sites in the same way that local currencies do in Bristol Stroud Lewes Brixton and other transition towns. The benefits of keeping money circulating within a local community is still applicable to an international community. Collectors of Postcards, stamps, old coins, etc. often make purchases on line of just a few pounds and choose to pay by cheque, or even postage stamps, within their own country, but this is not possible for international transactions, even within the euro-zone. Often the alternative is Paypal which costs a very significant part of the transaction, exactly the type of leakage a local currency is designed to prevent.
There are still many countries that paypal does not recognise. A complementary currency would avoid these charges and could be used by a collector in any country. Before there were internet sites many collectors would meet at fairs and continue to exchange items by correspondance, but internationally this was often limited to barter, as there is no international money, especially one that can be sent by post. The currency I am suggesting would be a voucher for the currency issuers online shop and any other collectors registered on the site. There will be no exchange back to sterling or any other fiat currency, so it would be very difficult for any postal thief to dispose of the currency, especially if the sender had noter the serial N°s., more difficult, in fact, than for the postcards or stamps travelling in the oposite direction.
The currency issuer would however back the currency 100% with collectable assets in their online and on-street shop. The real value of the currency to a collector would be of course that they could buy collectables with it, but the issuer will always keep a suply of mint stamps valid for postage in each of the major countries and for sale at face value in exchange for the complementary currency. These would be mainly permanent value stamps, such as 1st or 2nd class UK stamps, and this would be part of the back-up for the currency allowing it to hold its real value. One currency unit would always be worth about 8 UK 2nd class stamps and so its value in sterling would rise over time. Its value would be based on a range of items, not just the UK 2nd class stamp so it wouldn’t have gone up by 38% this year as the stamp has, but certainly by 5% making it a collectable in itself.