@Nicolas_Swisscom, Having a specific "set control" vs a "random control" changes the way the results are displayed. The OOTB setting is to use random control however the KB you have referenced shows what it would look like if you were to have selected a specific experience as the control. I can see how this is a bit confusing at first if you weren't aware of the difference. Please let me know if you would like me to clarify anything. If you reply please tag me with @Docea so that I see it.Mihnea...

@mattrothstein, Because the content chagne delivered in Activity1 ExpB does not have a physiscal web address that you can reference as the starting point in Activity2 ExpA the best way to accomplish this is to create Activity 2 and then edit the ExpA (Default) with the same content changes which were made in Activity1 ExpB this will make it so your starting point is the modified content. The rest of the experiences can be the other variants.Hope this helps--Mihnea Docea

@SCB Thanks for posting this question. I think you are looking for something similar to the Audience Map provided in Analytics that gives you an idea of how many visitors you can expect to qualify into the audience is that correct? Is this what you are looking for in Target:

@MayuriK,The simple way to do it woudl be to build audience around if referrer URL contains "receipt" however this would only function for those who immediately return to the homepage after getting the receipt. It seems a more comprehensive solution would indeed be one that leverages profile data as @AL85 has suggested.