I love this article. DAGs seem to show up everywhere. I used them in a gene assembly program I wrote.
I am now working on groom email lists and this article is worth it's weight in platinum to me.
I do see a challange though. The redirects may not occur in an email system you have access to. If you send a broadcast to a group of customers, you will not see the redirects because they occur in the customer's email system.
At my former employer, when an employee quit, we made a redirect from the salesperson's mailbox to the sales manager's mailbox. When the sales manager quit, the redirect went to his boss.
So the question is how to track the redirects from the marketing communications company. I do not think you can.
I still loved the article though.
Nick Stein