DJ over at Bronto blog has a post up about list churn / list attrition. She quotes a statistic published by Loren from MediaPost (the original post is behind a subscription wall) that a list will lose 30% of their subscribers year over year. This is similar to a statistic that I use, but the context I have seen the published statistic in is slightly different. DJ offers suggestions on how to reduce this churn. All the suggestions are great, but I think that they slightly miss the point. There are multiple processes that can be described as list churn. One is churn DJ addresses, that is people unsubscribe from a mailing list. The other is people abandon their email addresses. Individual mailers have some control over the first type of churn, but almost no control over the second.
I think the study Loren was quoting describes the second phenomenon not the first. In 2002, ReturnPath published a study that showed 31% of people changed email addresses in a single year. Understand, this does not mean that 31% of recipients on any particular list will actively decide to unsubscribe from a list or report it as spam or otherwise unsubscribe from that list. This is 31% of all email address owners will get a new address and abandon their current one. There are a few reasons for the churn.
- Email addresses provided through an employer do not carry to new employers.
- Recipients change ISPs.
- Recipients change email addresses at ISPs, often to avoid high levels of spam.
Engaging users may help convince them that mail is worth enough to subscribe with their new address. However, senders will still see addresses drop off their lists. The person behind the email address is no longer using that address.
Not all subscription and delivery problems are under the control of the sender. Address abandonment is one of those problems.