The surprising first thing ever sold online

It's that time of year again: when Americans start flinging open their physical and digital wallets to take advantage of huge sales on Black Friday and Cyber Monday.

Last year, people spent a stunning $2.68 billion online on Cyber Monday alone. 

So, how'd this "ecommerce" thing get started anyway? What was the first thing purchased on the internet? 

Despite what Pizza Huts says, a large pie with mushrooms and extra cheese doesn't actually deserve the title. 

In a short video called "Proceed to Checkout: The Unexpected Story of how Ecommerce Started," producers from Shopify trace online shopping to its roots. 

It's a twisting tale that involves marijuana exchanges and a way-ahead-of-her-time grandmother.

Hint: The person responsible for the first item sold is probably watching every move you make. 

But you should really just watch the full video: