Agree with Michael! We use campaigns to also provide insight to sales as to the details of what the program was and how there person interacted with the campaign (using the advanced settings on the SFDC campaign) vs. simply responded, sent, etc. we custimize these so that sales can get an idea of exactly what the person did ex. stopped by booth, downloaed whitepaper, etc. we use these sames "statuses" for our lead progression steps in Marketo.