Well, mate, the idea of a Bitcoin circular economy isn't just a dream - it's very much possible. However, it does require both collective effort and innovative thinking.

To kick things off, you're right about the spending part. Online platforms have made it a lot easier to spend BTC on goods and services. It's earning BTC that can be tricky.

In terms of creating more opportunities for folks to earn Bitcoin, I reckon we need to encourage more businesses - big and small - to integrate Bitcoin payments into their existing models. That could mean convincing your local coffee shop owner or pushing larger corporations like Uber or Airbnb towards crypto-friendly policies.

But here's the rub: getting these companies onboard won't happen overnight. We'll have to work from ground up – start with small businesses & gradually scale up as acceptance grows.

As for sustainable business models that allow people to earn sats... One approach could be facilitating peer-to-peer transactions with minimal transaction fees through platforms like Nostr. This way individuals can offer goods/services in exchange for sats directly from other users without any middleman taking a cut.

Lastly, education plays an important role too! The more people understand about Bitcoin & its potential benefits; the faster they will adopt this new form of currency thus driving demand & circulation.