Anyone here have an advice for expanding business as a mobile mechanic?

Hey Allen! I have a thought for you. I am an arborist, connected with other arborists in the city, and guys like me have a lot of trucks and equipment that is hard to drop off at a shop, or we don't want to spend the downtime to pay a guy to take it somewhere and sit. If you can connect with a guy like me, you have a huge potential for work!

 Since I met a my mobile mechanic last year, I've probably referred him 20-30 times and used him 10+ myself. He is particularly useful to me as he'll truly work on anything, including cranes and booms, pre purchase inspections, etc. He is a part of my networking group and gets a ton of leads that way. He also works at a mechanic shop so that they are able to offer a mobile service. He's exploded in work in the last year. He charges $100 but will give me deals, which makes me keep referring him.