[genewitch]

I use CC for most of my "work", and it's pretty clear to me what "commercial" means. If someone uses my work to earn any money, then it's commercial. Unless they contact me and explain why it isn't, then i can grant them a license that allows them that.

This is only relevant if the CC is CC-NC, otherwise commercial use is "ok". it's pretty straightforward.

[johannes1234321]

Is it commercial if a non-profit sports club uses it to collect member fees?

Is it fornprofit if I use it and somewhere in a small note on my website it has a way to give me a tip?

It's trivial to come up with more such cases.

And you being fine with my usage, doesn't mean I can rely on it.

And then let's go international.

In case of doubt the answer is to avoid it, which can be fine and match the author's intention. However it can be nom-trivial.