Those are simple because they are physical artifacts, but let us consider the process of using those for trade.
A thirteen year old wants to send $4 to his friend. He wants to put money in a pool to buy a 4-pack of Terraria on a Steam sale for $10. He will receive one of the copies for his $4. His friend lives in another state.
He buys an envelope for 20 cents. He buys a stamp for 46 cents. He tries to look up his friend address on Facebook. It's not there. He sends his friend a text message, asking his address.
He addresses the envelope with his friend's address and his own return address. He licks and places the stamp in the top-right corner. He folds the dollar bills in a piece of scrap paper from the printer. He seals the envelope and drops it in a mailbox.
Several days later, his friend receives the $4. The friend deposits this with his own $6 to get a Visa prepaid debit card. Friend uses the prepaid card to buy Terraria on Steam, a gaming service which requires an account and email address.
Now, consider a transaction of $50 for a baseball card. Sending cash in the mail requires two stamps and two envelopes.
Who sends the letter first? What happens if one letter doesn't arrive?
Even stamps and baseball cards can present challenges for real-world transactions where physical co-presence between two parties is not possible.
A thirteen year old wants to send $4 to his friend. He wants to put money in a pool to buy a 4-pack of Terraria on a Steam sale for $10. He will receive one of the copies for his $4. His friend lives in another state.
He buys an envelope for 20 cents. He buys a stamp for 46 cents. He tries to look up his friend address on Facebook. It's not there. He sends his friend a text message, asking his address.
He addresses the envelope with his friend's address and his own return address. He licks and places the stamp in the top-right corner. He folds the dollar bills in a piece of scrap paper from the printer. He seals the envelope and drops it in a mailbox.
Several days later, his friend receives the $4. The friend deposits this with his own $6 to get a Visa prepaid debit card. Friend uses the prepaid card to buy Terraria on Steam, a gaming service which requires an account and email address.
Now, consider a transaction of $50 for a baseball card. Sending cash in the mail requires two stamps and two envelopes.
Who sends the letter first? What happens if one letter doesn't arrive?
Even stamps and baseball cards can present challenges for real-world transactions where physical co-presence between two parties is not possible.