The “Marketing Channel” is the main entry point for any analysis on digital campaign performance in today’s Web Analytics world. But how good is a channel if you can only see how much money it earned you, but not how much you spent on it?
Both Google and Adobe Analytics do not make it easy here.
While there is no way to get the cost per channel into Google Analytics apart from the context of the Multi-Channel Funnel Reports,, Adobe offers a somewhat hidden trick. And you can go full circle: Cost->Revenue->Refunds = the real ROAS.