Haven't found a single person that has reported actually getting paid by them. It's all complaints, and here is mine as well: I made several purchases using Coupay and although they successfully tracked the site visits, they never report any purchases made through their links, so you end up with absolutely no cashback... ever.
They promise high payouts and a $5 signup bonus, but you will never see either. They require $25 in accrued cashback before they will send you a check, but since your purchases never show up, you will never reach that. They keep all the money.
With dozens of cashback programs out there, don't waste your time with this one, regardless of their claimed payout commissions. You'll never see them.