Measuring non-profit and government websites is a bit more challenging. You need to figure out your goals and measure how efficient you are in achieving them. Every organization needs money to operate. In a non-commerce environment, the objective won’t be profit, but rather achieving more with less.
For non-profit, here are just some ways to incorporate non-commerce goals into the financial statement:
The cost of attracting volunteers and optimizing to bring that number down
The cost of attracting donations (how much do you spend for every dollar collected) and optimizing to bring that number down
For government and advocacy sites – cost per visitor (you want to spread your message further for less) and cost per engagement.
Here are some articles that will be useful: