[ghaff]

I'd add that what people here are calling a "side hustle" is something that quite a few people without a lot of marketable skills would call a job/income stream. And, yes, there are a lot of jobs/income streams that work for individuals who lack a lot of alternatives that don't work for companies that have offices, accountants, etc.

[ska]

I think what makes it a "side hustle" is that it is practical to do on top of a full time job (multiple jobs). Obviously if you scale the number of machines up it starts to look more like a small business, but it looks practical to do one or two machines in your "spare" time.

[skelseys]

There are a lot of opportunities like this. However, when you look at many of them in detail, they pay very very poorly.

[bluGill]

As a sole operator though the pay is better because you don't have overhead. If you pay a helper, some of the net income goes to you as the manager, and some to them (you can split that up however you choose). In some businesses management is hard and so the manager can skim off the top of their employees and yet their great management skills can pay the employees more than they would get along. This isn't one of those business where skilled management is required though, so a manager is just skimming off the top and a good employee will soon figure out they can start their own business and make more money without the manager.