However, the inbox environment has changed in many ways since I wrote that column:
The rise of smartphones and tablets – Mobile readership is typically above 50% for brands, causing email design and content challenges. But even more important is mobile context -- how and where consumers interact with your emails and Web sites.
Channel competition – Social, SMS, mobile apps and push notifications are becoming growing alternatives or competition for attention, especially among younger consumers.
Increased sending frequency from most brands, especially retailers – The average retailer sends four broadcast emails a week (many are sending five or six), up from about two per week in 2008.
The Gmail Factor – Today, Gmail addresses are often the largest percentage of a B2C marketer's database, up from probably second or third six years ago.
Growth of affordable marketing automation/personalization technologies – The ability to deliver on the "1 to 1 marketing" dream is now within reach for nearly all marketers.
All of these factors affect list churn in one way or another, either to aggravate it (increased frequency without relevance) or to ameliorate it (more relevant emails reducing inactivity or spam complaints).
Types of Churn
Churn comes in two types:
Transparent churn: Unsubscribes, hard bounces and spam complaints. You can no longer email these people because of a subscriber's direct or indirect action.
Opaque churn: Subscribers who have completely disengaged with your email program, including inactive readers who ignore your emails, leave them in a spam folder or let your messages pile up at email accounts they rarely or no longer use.
While transparent churn rates can vary widely, typical annual rates are between 25% and 50%. Opaque churn rates are probably between 10% and 25% annually for most brands, although I'm not aware of any solid industrywide research on this.
Causes of Email Churn
Email address churn is a fact of life for marketers. Some address churn is primarily driven by the quality and effectiveness of your marketing program (controllable) and some by changes in a subscriber's life and interests (uncontrollable):
In a future column, I'll look at suggestions for managing and reducing churn. Until then, let me know what you're seeing in your own database and whether you've taken steps to get churn under control.
Until next time, take it up a notch!