Do people exchange X thing for other things? If the answer is yes, IMO it's a currency, regardless of whether you used it in the past or not, or whether it's wi

Do people exchange X thing for other things? If the answer is yes, IMO it's a currency, regardless of whether you used it in the past or not, or whether it's widely used or not. You're free to disagree. Also, from wikipedia: > A currency is a system of money in common use within a specific environment over time