Affirm shares soar on news of Amazon partnership for buy now, pay later

It's bad for the customer, since they risk getting fees for missed payments and will likely be charged interest on the loan. By offering this as an option, retailers are preying on people who are in such a bad financial position that they do not have savings and cannot qualify for a credit card or have maxed out their existing credit cards.

Someone putting together a Visa/Mastercard branded product with a similar "pay in N installments" model could easily outcompete them. You wouldn't have to negotiate entry with every merchant and develop new integrations-- it would just drop into the existing credit card infrastructure.