As I'm sure many of you will agree, customers primarily exist to drive us nuts. Case in point: customer provides me with a spreadsheet containing lots of fields, 3 of which are email, first name, and last name. As expected, he wants them imported to MW. I ask him, "Any other fields from this spreadsheet?" "No, that's all I need." So we sent several campaigns, get opens, unsubscribes, bounces, etc., and then he tells me, "I wish we had imported this here date column". Grrr. So my question is, can I re-import the csv, now containing the 4th field, to the same list? If so, what happens? I'm hoping that the re-import will see the existing records and add the 4th field to each of them, while leaving their open history, subscribe status, etc. intact, but is this a case of wishful thinking? If my dream scenario doesn't turn out to be the case, how can I get the 4 fields and the existing open/click/unsubscribe history to merge, or am I just out of luck? I can't find any forum history on this topic, so maybe I'm the only person to be lucky enough to have a customer like this.