For me one of the most surprising things to find in this mountain of emails was banner ads. Perhaps I have just tuned them out, or maybe I just don't pay enough attention. But ultimately the business man in me realized that people are selling ad space in their email blasts! This certainly doesn't make sense for all organizations, but for many others emails are another viable source of ad revenue. If I were selling a specific product I would likely be far less inclined to do this. Regardless, it is an interesting topic to consider, and as always it is informative to see a collection of how others have done this.