Earliest games like Mario and Space War used to be played in self-contained worlds. Each on a different machine, and online within it, not like connected to players in Tokyo, Minnesota, Rio, Champ Elysees, Madrid and Delhi all at once. Only in the console of that bar where there are ten other consoles but really no game is connected to the other one, playing at one booth means only playing there not, in a big show down where all stats were collected.
Then games started to come out that allowed you to play with multiple people, everyone had to sit in the same room with each other, within reach of the nearest controller, this happened before playing on the internet was a big option. Games like FIFA, sometimes World of Warcraft and the likes are still played like this. Also, #PUBG!
But ever since the internet connected players and created multiplayer worlds online whole communities formed, that were dedicated to the game, its fandom, sharing culture and making the world a tiny little shiny little global village.
These games that were fancier, such as, the World of Warcraft and Second Life, freed us from our own worlds, they gave us an escape, so real that we loved living online more than in our house that looked nothing like the Sims ones. This also freed the geographical ties, making games not bound to cafe’s, arcades places, bars, outside locations, they could be played anywhere, be it your work desk or home pc.
Within these communities that people formed through the little chat box and animation ties began to grow stronger, and the games turned into a melting pot of ideas and culture, such an american thing! People created ways to exchange goods and services, just like in any culture or community a small economy formed. This could be within a game, included trading, colluding and what not. This could be through an agreement within a game chat, external chat or a formal platform for buying and selling like Ebay.
After game developers became aware of this, they tried to capitalise on the moment and then tried to create games that allowed users to purchase upgrades and items with fiat currency. But, fiat is never good enough.