Earlier quoted context omitted.
I have a friend who's about to start selling CC processing to local merchants at 1.29%. (His commission is 1/3 of that I think, so in theory the processor can go below 1%)
There's no way that is sustainable. The cards generally pay back upwards of 1% in points or cashback, so any processor that can offer rates under 1% is losing money somewhere.
But there's another guy who claims to have negotiated for 0.4% processing fee. I don't know how that is even remotely possible.