Its Easy......
Its easy to make a ton of money if your running a business that people want you to service their accounts. Build your buiness around quality and not being the lowest price.
Also don't bother chasing accounts that only have you in when the health or fire dept are going to close them down. I would never clean a lot of the dumps shown on this site. The time spent tring to clean them you could do three easy accounts and make a ton more.
I have been in business for 21 years, doing both kitchens and air duct. Sorry to say, I made my money on air jobs. Spend a week in a commercial air job and walk with $15K-20K NET in your pocket, takes a lot of grease jobs to do that.
You don't do the each week, thats where the kitchen hood jobs fill in, but the air jobs give you a lot of profit FAST. My 2cents.