I have been on both sides of the coin in factoring. I used a fatof when growing my last business thru a broker. Whole I did receive the immediate liquidity on my invoicing which what I was looking for, I did not receive the other benefits that make the costs insignificant. Complete A/R management, credit screening and collections, to my growing company allows you to focus on what you are good at, and not on wondering where your cash is.
Now I provide factoring and cash advances to growing businesses and businesses that want to grow. Factoring receivables is part science and part art. The matter of defaults are not if they are going to happen but when.
With that said, you are better off setting up a referral agreement with a broker that you feel can provide your clients the best overall services.
Pm me if you need more info.