Some may know you anonymously by web behavior and some by online profiling, some may have a social view of you, some may have a very transactional view, some a "record" view of all things you have in the public world. It's not just compiling a 360 view of the customer, it's recognizing which David Baker, at what time, what channel and what behavior.
What is the primary piece of data or primary key that will be used in the future to identify you as a unique person matched across all the other systems? This seems like a simple question, but I assure you it's not that easy by any means. Project to the future and think, will the mobile number be the primary key that is stable across all your lifestage event changes (buying a home, moves in early stage etc.) and the shifting of email addresses? I still firmly believe the email address is going to be king as the primary key. The challenge is tracking this long-term and the cost to do so.
Think about all the email addresses you have today: one from your younger life that may be connected to your social networking profile, another for college, another for work -- and if you're like many Americans, you likely change that every few years. Factor in another for junk mail, another for shopping and opt-ins. Consumers are managing more complexity around their lives through many profiles. That is a major challenge for marketers to deliver on a 360 view and fully connected engagement.
As you are building your email database and marketing to your customers, the question you need to address is not the responsiveness of the email address or future of the channel, but what is the real value of the email address in mapping behavior, context to how consumers will engage with you and the interconnection between identities. If you believe that, your email database has so much more value than a direct marketing output.
The industry often talks about attrition of the email database, talks about purging old email addresses or inactive email addresses. These are tactics and very linear thinking that solve only one dimension of your business challenge: customer recognition. Nothing can be enabled without accuracy in identifying your customers/prospects.
I recognize we should not send email to nonresponsive customers and should be more targeted and relevant, yet an email address is an institutional asset that has more value now and in the future. The channel is not going to die. How we use it may change, the direct response may diminish to some degree, but the email address is a key to the industry in how we recognize customers, and will become more prominent as the social profile evolves.
Net message of this article is: Think about the assets you have, think about email more broadly than a channel and begin thinking about how you will gain a clear view of your customer in the future. Duplicity in the database world is the greatest expense to both infrastructure and marketing.