Hard to say because I have only been at SFI for 2 weeks. I guess if people buy from your ECAs your more likely to garner a greater income, unless your PSAs are active enough and are doing what you are doing by having their own PSAs and ECAs through duplication, that would very likely garner a far greater income that just your ECAs.
It is very important to use both streams to get the highest income, which seems to be limitless. Hope this helped.