Interaction between paid & unattributed traffic

You have a paid marcom campaign - you take it off - and suddenly you find a drop in unattributed traffic.

Let us take a hypothetical scenario.
Weekly traffic dropped 40% as a result of taking out a campaign that generated approximately 10,000 visits a week. The expected fall was 25%, but there is an extra 15% fall due to drop in unattributed/direct load traffic. You are perplexed :O
What caused this?

This can be graphically represented as a bridge chart:






In this post, let us go through a workflow of how to mine this information and communicate this to business stakeholders
(After all presentation is an art - if you can't present your idea through, it will never get implemented)

STEPS TO FOLLOW/DRILLDOWN THE PROBLEM
Here I would say are the steps to follow before we decide to take out a campaign

I) Capture the first time and repeat visits that resulted from the ODG Campaign for the last few days (maximum of 90 days)
Calculate the Revenue per visit separately for each
II) Arrive at a statement:
"Campaign C results in an average of x visits a week landing from a campaign and y visits that did not land on the campaign on the same visit but on a prior visit"
III) Revenue Impact of removing the campaign would be
x*px + y*py where px and py are the average RPV for the x and y visits

Now let us go through an actual workflow of analyzing this information:

DETAILED ANALYSIS
Step I:
Job to be done: Capture the visits that resulted from the ODG Campaign for the last few days
Method: Create a visit segment with a condition on traffic source as from campaign


Get the visits for above segment - it is x.

Job to be done: Capture the visits wherein the user had not used the campaign on the same visit but on a prior visit
Method: Visitor Segment with condition on traffic source as from campaign and visit_sequence_number > 1


Get visits for above segment - it is w.
Then y = w-x i.e. visits that came to your site as direct load - but on a different visit had seen the campaign.




Step II:
Here is what we found:
"Campaign C results in an average of 10000 visits a week landing from a campaign and 6000 visits that did not land on the campaign on the same visit but on a prior visit. Their RPVs are $4 and $6 respectively."

So revenue impact of removing this campaign is
10000 * 4 + 6000 * 6 = 76000


This is just a directional workflow
So when you take out a campaign, bear in mind that you might be impacting direct traffic as well.