Author here. I'm sure you're right. I pretty certain I could have charged them much much more and they'd still have accepted it.

In conversation with the software eng it was implied that they intended to send someone on site to each of over 500 sites to reimage the devices. That must have cost them way more than £70/month and the way that after ~10 months the number of devices actually went up to over 1,000 suggests they were happy to just keep paying.

The thing is, it was essentially no work. All I did was remove a firewall rule. I had to run NTP anyway for my regular customers. Initially more time was spent just in email back and forth and honestly I was enjoying that.

Because of it being basically no work, I had a moral problem with trying to find the absolute highest amount of money they would bear.

I know that is wrong and it does me no good, but I couldn't get past it.

What did annoy me was their inability to pay bills on time, and time I spent chasing invoices and creating custom late payment paperwork that is never relevant for my usual customers.

That was the main impetus for doubling the rate, and despite me jokingly suggesting that their product was not good enough to be profitable (I have no real data on that either way) I suspect they had much bigger organisational problems to be consistently paying late and ending up insolvent.

I like your attitude. If you were stuck fixing the mess the software engineer had to fix, you'd appreciate a random stranger making your life easier when they didn't need to. Maybe they'll pay it forward. Think of the money you didn't charge as your donation to making the world an ever so slightly nicer place!

Presumably the customers were SoL. That’s the problem with everything being run “in the cloud.”