title: nservicebus persistance data - what is it?
body: <p>as I was reading thru documentation on nservicebus, I wasnt able to find what is persisted under Persistence section.</p>
  
  <p>If nservicebus is a loosely coupled distributed library sending self-contained messages, what is there to persist? I dont understand.</p>
  
  <p>With web app, when a user has a Session, we may choose to persist the Session in SQL Server, in Memory or somehow else, but with nservicebus there is no session to persist. </p>
  
  <p>So, what is actually the Persistence in nservicebus? 
  What sort of data that could be persisted and for what reason?</p>