How do Independent Insurance Agents make money?

I just got insurance on a new car through an independent insurance agent I found through Facebook. It was a unique experience calling and texting him at home on his personal phone for insurance, let alone on a Sunday. Not to mention his using a Gmail account. He got me a great quote that's for sure.

My question is how do these people make money from this? For the service he provided me I feel like I could give back in return, but he did this for free! Does he get something from the insurance company?