We have multiple email programs that we can send to the same person multiple times. We calculate our campaign stats in SFDC using formulas from campaign statuses sent from Marketo (i.e. Sent, Delivered, Opened, Clicked, Responded, Unsubscribed). We have smart campaigns set up to change the campaign status based on the contact's activity.
When a contact is sent an email more than once, the stats for that contact are being overridden instead of averaging out each time they are sent a specific campaign in SFDC. (i.e. Lead A is sent Campaign 1 and clicks the campaign, the next time Lead A is sent campaign 1 they only open the campaign. Stats are being changed to 0% clicked and 100% opened, instead of 100% opened 50% clicked).
Is there anyway to have these campaign stats averaged out in SFDC instead of being overridden? What could be sent to SFDC from Marketo as a trigger that the lead has gone through the campaign again and to average out these stats instead of overriding them?