Subscriber Engagement and Your Inbox Placement Rates

Have an email database filled with subscribers that aren’t opening or clicking? Or a database full of email addresses that aren’t active with their inbox? You’re likely suffering from Inbox Placement issues.

For some time now, we’ve known that Mailbox Providers are looking at subscriber engagement to help determine where to filter a brand’s email. Not surprisingly, we work with a lot of clients to help them understand how a lack of email engagement can affect their inbox placement. Yet, many senders still don’t understand the link between subscriber engagement and inbox placement – until it’s too late.

To demonstrate the relationship between engagement and inbox placement, I analyzed the reactivation campaigns from some large marketers. (Interested in learning more about reengagement campaigns? Check out Return Path’s recent webinar and research study.) To do this analysis, I identified several reactivation (also commonly referred to as “win-back” or “reengagement”) campaigns based on subject line keywords and content analysis using Return Path’s Inbox Insight product.

After I was able to identify campaigns that were targeting inactive email subscribers, I looked at the metrics for these individual campaigns vs. the overall metrics for the month the campaign was deployed. Please note, that while subject lines and content can help determine which emails are likely sent to subscribers that haven’t engaged with a brand’s email program for an extended period of time, the “inactive” period for each brand is unique. In addition, the quality of the subscribers on the file, the age of the email list, the vertical, the perception of the  brand by subscribers, the amount of emails regularly received by the subscribers from the brand as well as other brands, and the source of the email address all play a role is these engagement metrics. However, it is pretty clear that no matter the brand, sending to inactive email subscribers affects inbox placement rates.

Let’s start with the obvious. Some brands have better overall engagement than other brands. We can see that in figure 1. Brand A’s average monthly read rate is above 25% for each month evaluated. Brand G, on the other hand, has an overall read rate of 17%. But, what is also obvious for all brands (except for one campaign for Brand F), the reengagement campaigns have a read rate well below the overall monthly read rate for these senders. In general, these campaigns have a read rate below 10% with many campaigns having read rates below 5%. Given that the audiences for these campaigns have been disengaged with the brand’s email program for an extended period of time, this is not surprising.


Figure 1 

Now let’s look at the ISP-marked spam rates for these reactivation campaigns compared to the monthly ISP-marked spam rates for these brands. In Figure 2 below, we can see that generally, these big brands have very respectable ISP-marked spam rates. However, for campaigns that target inactive subscribers, the ISP-marked spam rate is often 3-5 times higher than the average monthly rate. Having the emails delivered to the spam folder is likely another contributing factor to the lower read rates we see above.  Interestingly, Brand B had a very high read rate for their reengagement campaign, but also had one of the higher ISP-marked spam rates for their reengagement campaign. While Brand C had low ISP-marked spam rates overall and for their reactivation campaigns, Brands D and G had high ISP-marked spam rates for all of their win-back campaigns.


Figure 2

In the end, who you have in your email database matters. If you are sending campaigns (reactivation or normal broadcast campaigns) to inactive subscribers, your inbox placement can suffer. And in the end, this hurts your bottom line. In order to mitigate your risk, we recommend creating a throttling schedule to test what works for your brand and to carefully monitor your placement and sender reputation metrics throughout the process.  By understanding what you are sending to whom, you can better manage your email program overall and continue to reap the benefits of this profitable channel.





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