Here is the ROI report from sell.do which gives you insights on the campaign ROI with the help of which you can eventually measure the success of your campaign. With help of these reports, you can also plan/estimate your next campaign activities in order to increase the campaign performances.
Campaign ROI reports can be viewed directly by using “dashboard” action icon under campaigns and also from Reports > Marketing Reports.
As you can see in below screenshot, it provides the following information
Cost per site-visit
Cost per booking
You can also customize the report for certain period of time or for certain sources or sub-sources. Also, you can the filter report with either New leads or Re-engaged leads or both.