The concept

Boleto is an asynchronous payment method. The buyer closes the order, receives the document, and pays whenever they want, within the due date. The sale is only confirmed after the payment clears, which takes business days.

This creates two realities the seller needs to manage. The first is that a boleto issued is not a sale, because a considerable share is simply never paid. The second is that access to the product can only be granted upon confirmation, never upon issuance.

On the upside, boleto is not subject to chargeback, because there is no card to dispute.

How it shows up in practice

You sell infoproduct in Brazil and offer boleto as payment option. A customer generates the boleto to pay tomorrow, but gives up the week after. You received nothing because generated boleto isn't a sale, payment needs to be cleared before you're sure that money is yours. You learn you need to count on a considerable rate of non-payment on issued boletos.

We see our customers as invited guests to a party, and we are the hosts. It is our job every day to make every important aspect of the customer experience a little bit better.

Jeff Bezos Source: Jeff Bezos's letters to Amazon shareholders.

The advantage is boleto doesn't suffer chargeback, because there's no card to dispute. Operational reality is you can only unlock product access on payment confirmation, never on boleto issuance, and need to manage the list of customers who generated boletos but never paid.