I feel like the retailer side makes sense, even if you do 0% APR. The alternative to Affirm's merchant fee is a credit card merchant fee (say, 2.9%).
Affirm takes what would be a ~$600 or $2000 credit card transaction and turns it into a series of ACH payments. If (cost of ACH + cost of underwriting) < (cost of credit card merchant fee) then the merchant and affirm can split the difference.
Affirm takes what would be a ~$600 or $2000 credit card transaction and turns it into a series of ACH payments. If (cost of ACH + cost of underwriting) < (cost of credit card merchant fee) then the merchant and affirm can split the difference.