Here here. I run my business on the side, been doing so for I think 17 years now. Might not be my main income, and even if it was I would run my business the same way I do now.
If customers want to be nickel and dimed they will end up at Best Buy, even if they start with you. I can undercut every other tech business I know in the city because my costs are next to nothing, even if I were larger I wouldn't be spending more for costs.
Once customers see they can get fast, great service, onsite and with a smile, they come back. Though some of my customers are now close friends I always tell them I hope not to see them soon for anything IT related, if I do see them soon it is because I failed to do the job right the first time, and for that it is my fault.
I'm really not trying to point fingers, but I see people everywhere not willing to share information and trying to find how to make more money doing something that should essentially be free, even in these forums. To me, if a customer or other tech wants to know how to do what I do or how I do it, there is little that is a "company secret". Sure, I keep some specifics like configs less public knowledge, but lets face it, if someone wants to know how your business runs, and they are a customer, they know most everything there is to know. Your remote software, invoicing and crm systems, if your using dSS they have 100% of your configs, they will see d7II and be able to find what it is, what they don't have is your experience, and that is something they can't just watch you do or copy.
For my day job I work in IT with over 8,000 pc's and an overall team of 20+, of which there are about 8 of us that work together daily. We share all kinds of information, don't charge each other anything for it and yet we are still experts at our specific tasks. It seems like a tangent to some maybe but I think not sharing with your customers is also milking them too much. Why can't you share your knowledge with them, are you afraid they won't need you anymore? If yes, you are offering nothing to them and probably shouldn't be charging for it anyway. Everyone can run patchmypc, ninite, Windows Updates, install an AV and, and, and... Forums everywhere even tell them to do all this as part of canned messages.
Be the difference, be something others don't offer. Train, teach, share, explain and most of all look at how you price it all. I have a large customer base, all willing to return, the spread my company name all over, I'm plenty busy and I can't complain about how much I make. I spend less well less than $1,000 a year to run the business and not a cent on advertising.