Attrition
Yes, Virginia, there is list churn
Yesterday I talked about how data collection, management, and maintenance play a crucial role in deliverability. I mentioned, briefly, the idea that bad data can accumulate on a list that isn’t well managed. Today I’d like to dig into that a little more and talk about the non-permanence of email addresses.
A common statistic used to describe list churn is that 30% of addresses become invalid in a year. This was research done by Return Path back in the early 2000’s. The actual research report is hard to find, but I found a couple articles and press releases discussing the info.
List Attrition
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.