Well one difference is being able to easily propagate failures end to end. Agreed about idempotent processes in the "consumer" processes. But I generally prefe

Well one difference is being able to easily propagate failures end to end. Agreed about idempotent processes in the "consumer" processes. But I generally prefer marking an end user session in a persistent store before propagating the request for payment (effectively acting as a sticky current transaction ID), and making synchronous requests down the chain versus generating a transaction ID and doing a bunch of async message queuing. It's just easier to know when something didn't work and display the appropriate user feedback. But your point is valid.