One hot topic at the recent Email Insider Summit in Park City, Utah, centered on the role and value of email preference centers. As with other email-marketing disputes, the debate that emerged from a panel discussion reflected general disagreement over the details and how marketers implement preference center, rather than focusing on the bigger picture.

"Relevance" used to be the biggest catchphrase in email marketing, followed closely by "it depends," which is a favorite among email strategists (especially Andrew Kordek). However, both these terms seem to be losing ground to "Big Data." We now live in a world where 2.5 quintillion bytes of data are created each day, according to IBM. In the world of email marketing, where there is big data, you will also find relevance. Big data is a large topic with many facets, but when it comes to email marketing, there are a few things you need to do:

Last month I called out some of my deliverability friends for focusing too much on inbox placement and not enough on the revenue implications of mailing less. Sometimes "more, more, more" is the right answer at the individual level. Unfortunately, the sum result of all those decisions to send more mail is that we're sending a lot more email collectively. Many "more, more, more" proponents don't see the broader, "environmental" impact of constantly taking that approach. They think the deliverability folks (like me) are alarmists, and refuse to believe that the email ecosystem is going to change. They're wrong.

Every month, it seems a new report is released announcing that more people are buying and using their smartphones to browse websites, send email, watch sale items and even make purchases. Some brands report as many as 40% of their opens come from mobile devices. Unfortunately, the explosion in mobile opens has not translated into an explosion in mobile clicks, and many brands are now seeing troubling declines in their engagement metrics. What's even more troubling, though, is that many of these brands aren't doing anything about it.

Without a doubt, the most frequently asked question in email marketing today is "How do we address the growing number of subscribers who are reading our emails on mobile devices?" Specifically, the question becomes: "How do we design our emails to render well and provide a good user experience, no matter which device the email viewer uses?"

Now is the customary time to make predictions about the trends that will have the greatest impact on the email industry in the coming year. Only this year I'd like to focus not just on the trends, but also on how they should affect what we do as email marketers. Knowing what is going on is only useful if we adjust our tactics because of it (kind of like email metrics themselves).

As we assemble in Deer Valley for the 14th Email Insider Summit, we look forward to a very full agenda. While the industry may have seen a crazy transition to mobile viewership/engagement, it's still grappling with the same issues we've had for years, such as justifying email marketing, when the perception is that it's not effective as moving the numbers (a perception that's hard to swallow for those that live and breathe the channel!)

It's amazing that it's December already and time for the Email Insider Summit in Park City. Sadly, I won't be there. Thanks to a 50-MPH wind that caught hold of my car door and slammed my head, I now have the kind of injury typically sustained by football and hockey players: a concussion. At the advice of my doctor, I won't be on a plane for a few more weeks, but I will be there in spirit! As part of the neurological assessment I endured, I was asked about words that begin with the letter... well, take your pick. Oddly …

The email marketing holiday season is constantly evolving. Every year there are things that surprise me, as well as things that, thankfully, don't. Here are some highlights so far: