Read on to learn how to identify who's still paying attention, use re-engagement techniques for those who aren't, and improve the relationship you have with the people on your lists. All email marketers have inactive subscribers who haunt lists and cost money with seemingly little return. Having a follower with no recorded opens can mean a number of things. Whatever your reasons for staying silent, having too many subscribers not engaging with your campaigns I.E. Opens, clicks and more can be costly. Conversely, engaged lists mean better inbox placement and a better return on your email spend (roi). Let's see how to measure engagement, how company mailing list engagement affects roi, and how to create a re-engagement campaign. How engaged are your subscriber lists? Good email marketing is sending high quality content to a list of people who have opted in to receive content from you. “engagement” is its measure. Most often, it is represented by the ratio of opens and clicks over a period of time. We looked At 18,000 active subscriber lists (the ones that were used to send out a campaign in 2013) and categorized them with a few new names, to help you identify different levels of engagement in your own lists. Note that subscribers who had not yet received a campaign were not included:category open and/or click frequency % in average subscriber list very active 2+ times in the last 3 months (90 days) 3.28% asset at least once in the last month (30 days) 21.24% engaged