Eric,
I don't understand the story you're trying to tell with your chart of customers on the y axis and campaigns on the x-axis.
Are you trying to ask which campaigns are most associated with customers?
If that's the case, then you could count the number of customers for each campaign - or even better for each campaign type. Then you could rank them.
Alternatively, you could also count how many campaigns each customers was a part of, and see if there is anything interesting in that data.
But I wouldn't want to look at that giant chart.