This is missing some testing. In multichannel environments you have the potential for multiple touches, as well as baseline if your company is large enough. For example, a traditional product like cars: you have a baseline of folks who come in, and then you have (ideally addtional/higher rate of) folks that come through the digital channel, such as engaging an online salesperson. Do the digital channels generate a higher rate of purchase than the baseline channel? If so, is the lift statistically significant? These are what I mean. Revenue moving through a digital pipeline could be because people happened to fall into that bucket but were already going to purchase anyway. In other words, some of the $1000 went to non-incremental marketing. The goal is to make sure the incremental marketing exceeds the spend.