How to do your first mailing list inventory

Performing a mailing list inventory is not an easy task but it has many benefits and should be undertaken once every few years.  Among the benefits:

• Reducing list fatigue
• Increasing open rates
• Improving click-through rates
• Enhancing publisher reputation
• Detecting new segments
• Reducing overhead by strategically shuttering or merging newsletters

As I define it, a mailing list inventory cross references various data points of every newsletter sent by one brand or publisher. Those statistics primarily include the total number of subscribers for each newsletter and the overlap of subscribers between each. Your company's email management team can attain this information, however it may take some time to assemble depending on the number of newsletters. A matrix of the data would look like this:

From the raw numbers a breakdown of per-list overlap percentages can then be tabulated.

The data can be surprising. In the example above, notice that some lists are nearly 90% duplicated in another list, while some are niche focused with only single digit overlap. Real strategy can now be formulated to improve everything from conversions to branding to editorial overhead. It also might give you insight into shifts in your audience's needs.

You will also want information about each list's average newsletter open and click-through rates over the prior year. I specify newsletter here so that ad blasts or surveys do not skew your numbers. This data is a benchmark for future performance after changes have been made to your mailing lists and newsletters.

The spreadsheet depicted above can be obtained here. If you have questions about the process or suggestions on better handling this matter, please drop a comment into the post and I will respond. Please also send along success stories and creative outcomes. Those would be great to hear and share.