Hidden Metrics: What You Don't Know CAN Hurt You

Have you ever wished people would hide the hurtful truth from you? I certainly would have enjoyed my Christmas more as a kid if my older brother hadn’t spilled the beans about Santa. I still remember the words he uttered, “You know, Santa Claus isn’t real.” As a little girl, those words hit me like a ton of bricks and Christmas was never the same afterward.

They say that ignorance is bliss, and in my case it most definitely was, but what about when it comes to your email program? Do you really want to miss out on any additional insights that can help you gauge how successful or unsuccessful your email marketing strategy is? Better data positions you to make better decisions about your email program–decisions that could make or break your email program’s success.

As an email marketer, you’re probably already looking at open rate, click rate, click-through rate, delivered rate, and more. But, are you looking at real engagement metrics that mailbox providers themselves care about? These are metrics your ESP can’t provide, so we like to call them “hidden metrics.” These “hidden metrics” are vital because they determine whether your emails reach your subscribers. They also tell a story about how your subscribers feel or react to messages you send to them.

Spam placement rate: A low spam placement rate signifies you’re a trusted sender in the eyes of the mailbox provider and that subscribers want your emails. An increase in spam placement could point to issues with a specific campaign, or your entire email program. In our lastest report, we found that the average spam placement rate in 2015 was 12%.

“This is not spam” rateOnly emails that land in the spam folder can generate a “this is not spam” vote; therefore, a low “this is not spam” rate could be an indicator that few of your emails are being sent to the spam folder in the first place. But if you have a low “this is not spam” rate and your actual spam placement rate is high, this tells us subscribers are not rescuing your mail from spam because they think it belongs there. This could be due to a lack of permission, poor recognition of your brand, or a loss of interest from your subscribers. The average “this is not spam” rate in 2015 was 0.04%.

Read rate: This rate is similar to the open rate, but more accurate because it measures all emails viewed, regardless of images rendered. If read rates are low, and deliverability hasn’t changed, it may be a sign your subscribers are not resonating with your subject line. If read rates are high, your subscribers are finding your messages engaging and relevant. The average read rate in 2015 was 14%.

Complaint rate: When someone deliberately marks your message as spam, they are clearly showing dissatisfaction. It follows then that senders should strive for a low complaint rate, indicating their mail is wanted by subscribers. A high complaint rate at any mailbox provider can negatively impact your deliverability. The average complaint rate in 2015 was 0.18%.

Using the right metrics helps you determine whether your email program is win or a fail. Ignoring “hidden metrics” means you could be missing out on opportunities to optimize your email program and reach your overall goals. You can learn more about other metrics and how different industries stack up against each other in our new benchmark report, The Hidden Metrics of Email Deliverability.

minute read

Popular stories



BriteVerify email verification ensures that an email address actually exists in real-time


The #1 global data quality tool used by thousands of Salesforce admins


Insights and deliverability guidance from the only all-in-one email marketing solution

GridBuddy Cloud

Transform how you interact with your data through the versatility of grids.

Return Path

World-class deliverability applications to optimize email marketing programs

Trust Assessments

A revolutionary new solution for assessing Salesforce data quality


Validity for Email

Increase inbox placement and maximize subscriber reach with clean and actionable data

Validity for Data Management

Simplify data management with solutions that improve data quality and increase CRM adoption

Validity for Sales Productivity

Give your sales team back hours per day with tools designed to increase productivity and mitigate pipeline risks in real-time