In my quest to clean up our database I found Josh Hill's guest blog "How to Clean Up Your Marketo Database". The article is excellent and I highly suggest reading it if you're interested in doing some fine-tooth-comb cleaning.
One area that I am interested in cleaning up is removing the leads who have received several soft bounces in a row. For example, a lead whose e-mail is set up to automatically reply with a message indicating that they are no longer with a company.
Josh suggested setting up a trigger campaign to catch these leads and changing their data value to Marketing Suspended for 30 days:
My question is why set them to marketing suspended for 30 days? Why not remove them from the Marketo database (but keep them in SFDC)?*
*If I were to delete the lead I wouldn't do this using a trigger campaign - just a single campaign run.