In Beyond money, Ben Goertzel describes Offer Networks as a hypothetical system of exchange for goods and services that considers the failure of money to capture the nuances of productivity. Briefly, an Offer Network is a system of barter that includes property and currency and generally any "today stuff" or "tomorrow stuff", tangible and intangible, among the objects of the transactions to be systemically cleared.
The thought experiment is compelling. An Engineer or Technologist first asks how such a system can support itself, is it possible, and may arrive at an open source, peer to peer, voluntary boot-strap solution with solar powered mesh nodes. An Economist might reflect on the idea that scarcity in commodity or currency is a special case of trade value, and not the largest class of trade value in terms of transaction volume.
An Offer Network like the one proposed would have the potential to dramatically multiply economic productivity in terms of a general conception of trade value. To be successful on the medium term, the trade and collection of currency would be very important. The long term is over the horizon.
Dramatically multiplying economic productivity means that the economy, in general, expresses a far greater human potential or capacity -- if the Offer Network can scale to the spectrum of successful matching and clearing envisioned.
However if it can't be done technologically, at the moment, then at least the lesson learned from this thought process is (perhaps) to develop the concept of value with respect to productivity.