How to determine a good sales model for your product?

How do you guys figure out your sales models? Do you opensource projects and sell subscription licenses for commercial use. Do you keep it closed source and just collect subscriptions.

My specific project could be sold as a AWS instance actually. And so I could set it up with a price per hour that users pay and then Amazon sends me the $. Problem with this is I don't know how many domains they would serve so not easy to set pricing ranges. So I'm better off making a AWS template for my use and rent out the server myself with the software.

How do you do it?