In Renaissance Europe, Michelangelo and da Vinci painted masterpieces that have the world in awe. Fast forward to today and we occupy a connected world, and self-publishing platforms have turned all of us into content creators.

Our iPhone and Xbox 360 let us design and build avatars, social personas, and digital superheroes or athletes who “live” in our parallel reality. The 21st century is just as much about physical goods as it’s about the archetypes that occupy our fantasies.

It may not get easier to define exactly what the “real world” is anymore but one thing is certain: Attention spans are monetizable. Thanks to innovation, there’s an emerging marketplace for virtual collectibles, so long as they can be construed into a digital asset.

Blockchain firms such as 0xcert are converting unique, non-replaceable possessions into tokenized holdings. “Non-fungible things can be monetized vis-à-vis cryptographic coins, which are then immutably recorded on a blockchain database,” says a company spokesperson. “Tokenized assets can absolutely be bartered for other goods and services on trading platforms, just as thousands of years ago our ancestors bartered with commodities like seashells and goat’s milk.”

What if you tokenized properties like your home, college degree, poems, tattoo designs — would that be worth much? That’d depend on what you create. But a benefit of tokenization is that one-of-a-kind possessions can gain liquidity in a global marketplace.

Europe-based 0xcert (the first character is a numerical zero, not the letter “O”) and its blockchain developers are tokenizing non-fungible (non-replaceable) items using Ethereum’s ERC-721 standard. A third party authenticates the information and 0xcert issues digital certificates that validate ownership.

So what are other possibilities? Think NBA and NFL customized athletes; rifleman protagonists who shoot zombies in adventure games; and tailor-made, virtual goods.

Last year, Cryptokitties (a decentralized app whose kittens “live” on blockchain) clogged the Ethereum network when it went viral — tying 25% of network traffic during peak times. The game’s creator (Canada-based Dapper Labs) made a fortune and plans to release more dApp games.

Consider Disney’s intellectual properties: Mickey Mouse, Elsa, Donald Duck and the rest. In 2016 the Disney brand was valued at nearly $37 billion. The company has immense financial value because its characters resonate with a large audience.

Global art is more than a $40 billion market and the collectibles market is around $200 billion. Digital certificates mitigate the risk of theft, forgery, and unauthorized copies of one-of-a-kind pieces.

If our ancestors could barter seashells for silver thousands of years ago, then custom-built superheroes or athletes should be tradeable with someone who owns video-game avatars from Moscow or Tokyo.

In Web 3.0 economy, our imagination can be manifested into real life as token assets. Their god-like developers can profit from their unique creations.