I Fert 65 out of my 72 accounts with a blood meal and cottonseed meal mix (18-5-2) The other seven I use synthetic fert by request... these 7 accounts get more pest and fungus problems annually than the other 65 combined. (not that I mind, more $)
I use mirage, round up, etc in the beds, and spray for broad leafs in the lawns.
I still need to get paid...
And lets face it you cannot go to customers and say "you are going to have twice as many weeds, and it is going to cost you twice as much."
I switched to organic fert a year and a half ago after seeing the results over the course of a growing season.
I was paying 11 bucks for a 50# bag of chem fert (ferting some accounts 4-5 times a year) Now 13 bucks a bag twice a year, maybe.
Fert the soil not the plant.