I've only had one deal where a merchant asked about my commission. I've been funding the same merchant for two years and the last deal we did, I got him the best dollar amount/term/rate we've ever done. I didn't charge a PSF and he was happy about the deal so he wanted to make sure I was getting paid. I just told him that the funders pay me a fee for facilitating the deal. I think most merchants wont ask what you are making but I've been working with ISO's for the past few years not direct to merchant so I'm not too sure anymore.