It’s a great answer. But what about deals that opened after a campaign and closed during the campaign. Shouldn’t they be also considered? Why the deals started before the campaign should only be considered. When we check ROI of campaigns, we also consider the stage change/progress in deals and also new deals that were started. For example, one of our campaign would be around an industry event. Several deals will be a result of the event. But we cannot attribute them to the event promotion.
I think we should have flexibility to both attach and remove deals to be able to accurately measure the campaign performance as per our company needs.