I figure if you have a database of customers that represent more than 30% of your entire database, you're more than likely to have thought about this topic. You have an asset: an email address! How do you account for this asset? Is it a cost-saving proxy? Do you see it only as a channel proxy? But what does each individual email address mean to the value of a customer record?
I expect many look at cost compression as the first way to solve their budget and growth challenges and defend the costs of their operation. This is why we've seen such compression in the CPM space over the past three years.
An email address can be a cost-saving proxy. It can be accretive in revenue to all the other channels. It can be a combined asset value, as it drives engagement while other channels convert (email and on-store or email and search). It can be a lifetime value indicator that helps illustrate increased purchase frequency and a lower cost of sale. The value of an email address can be funnel-driven as well. You can look at it from an early lifecycle approach and derive a proxy that shows a prospect to customer and the incremental value of the email address through this stage. You can also use a late lifecycle proxy - like loyalty engagement.
You may ask, why would I need to do this in the first place? I already drive revenue through the channel, create brand engagement through the channel, and have an active reader and responder base. So, I challenge you to present this to your CEO and explain how this extends customer value to the business. To pull this off, you need to think about things a bit differently.