Why do we need service bus frameworks like NService Bus/MassTransit on top of message queuing systems like MSMQ/RabbitMQ etc?

Question

In the distributed message transaction world, am trying to understand the different parts that are involved in developing distributed systems. From what I understand you can

Answer 1

I can't comment directly on MassTransit, having only tinkered with it.

I use NServiceBus and am a fan of it. I think there are valid reasons for directly using queuing technology, but I think rolling your own ESB using MSMQ/RabbitMQ would cost a lot more than simply using a commercial product (or open source product e.g. MassTransit).

So do you need it? No. Will it make your life much easier if the features match your requirements? Absolutely.