Spending is a bizarre human activity; encompassing almost all aspects of modern life, evoking emotions, and fulfilling endless purposes. Yet, as much as one can love or hate spending, it’s hard to argue that the act has evolved drastically in the last millennia–making it easier than ever to exchange value within and beyond national borders. It can be interesting to think that, at a point not too far in our history, we used to trade predominantly with commodities in a system of bartering inste...