I never used one, but I'd assume they're as good at following the plan as you are (I had read some articles that said some of these lenders operate on voluntary repayment, no fees, no collections, but I don't know how widespread that was), but interest rate arbitrage has to be considered against the effort.

It's much less effort to use my everything credit card and get my 2% discount than to do a 0% apr over four months (or whatever), setup a new account, setup payment at that new account, remember to make the payments, etc and for what? Short term bank interest on most of my purchases would be peanuts, especially since I wasn't getting 2% bank interest when BNPL was at 0%.

I imagine there are a number of those out there, but I've taken many BNPL deals that were zero fee, zero interest. It truly worked out to be the exact same cost whether I paid upfront or took the BNPL.

I imagine the BNPL people made their money from the same kind of CC fee models and from customers who ended up not being able to stay within the 0% timeline. From my memory it usually had some big fines or interest rates if you couldn't make the payments.

I always imagined that the companies using the service at checkout would give the BNPL company a percentage of the sale if the customer used the service. Even if the price is the same for the consumer, BNPL companies could argue that they generated sales that might've backed out had they not been available.

This is exactly how they work. I work for an ecommerce company that offers one of these services. We pay them a small percentage and they take on the liability to collect payment and handle disputes. We already pay another percentage to try and detect fraud for a certain amount of our transactions. By letting the BNPL company act as the purchaser on behalf of the customer, we can offer them a cut of what we would have paid for fraud detection.

Exactly. The retailer pays the interest (a small marketing cost to increase customer spend), which is made into an offering to financiers of a low risk loan trenches, with absurdly high interest rate (20%+ APR).