At Viking-period emporia such as Kaupang and Birka there is an abundance of archaeological evidence of silver being used as money (Blackburn 2008; Pedersen 2008; Gustin 2011). This is understandable. Silver in various forms – coins or bullion – was a perfect medium of exchange, being durable, valuable, easily cut and weighed into desired quantities, and widely accepted as a means of payment in large parts of the Old World. For people living at these emporia, who had to trade off their produce to buy food and other necessities, and therefore performed transactions frequently, this medium must have been very practical to use, once it had become accessible (Skre 2011: 81–3; Williams 2011: 355). A commonly accepted medium of exchange expands the possibilities for exchange by enabling purchase and sale to be separated in time and space (see, e.g., Melitz 1974: 53–8).