From 2011 to 2015, Kevin Griffin and I ran a bootstrap startup for automated monitoring of Windows Servers. It was so much fun, so much work, but we shut it down in early 2015 due to a lack of traction with our paid offering.
I don't regret a minute of it.
We designed it to start out with defaults that didn't need tweaking for the majority of business servers (cloud and on-prem) and the ideal user was a small business that wanted to track their servers availability but didn't have a full-time server admin to implement a costly and complex traditional monitoring solution. It also didn't require an IT person to implement it. It was the easy button for server monitoring with built-in SMS alerts.
Since the service isn't around anymore, I thought I'd list some potential replacement services: