Question
How can my campaign have ROI for Objective but not Overall? Isn't Objective a subset of Overall?
Answer
It is possible to have an ROI for Objective but not for Overall. It may help to think of Overall as setting the Objective to "all visits"—the Overall report goes through the same ROI methodology. In this case, when tracking to all visits, the campaign performance did not exceed what “would have happened anyway” and therefore had no ROI to report. However, it did exceed when tracking to the selected Objective, so the Objective had an ROI.
