Email is still one of the most profitable and efficient hooks in your marketing tackle box. According to a recent report from ExactTarget, “68% of marketers believe email is core to their business.” If done right the income you earn from your brand devotees outweighs the costs of building your email lists and implementing an email marketing platform.

Nevertheless, caution is called for in email marketing. Poorly executed campaigns can leave you with disaffected or even hostile subscribers. It is absolutely vital to the well-being of your business to monitor your email marketing performance.

But what occurrences indicate that your email marketing campaigns are healthy? You must measure and analyse certain activities which you define as key performance indicators (KPIs). Aside from an overall increase in revenue, what can you measure in order to prove that your email marketing efforts are worth it?

Email marketing KPIs

The following is a short list of some typical KPIs used by email marketers to gauge campaign success. Optimal rates for any of these KPIs differ depending on the type of product you sell, so make sure to create your own baseline and improve your performance from there.

Bounce rate

This KPI lets you know whether the email you sent landed in your subscribers inbox or not. This is a pretty big deal for a couple of reasons. First, if the email never arrives your subscriber never sees it, and second, if your emails attract a high bounce rate then email service providers (ESPs) can block you from sending altogether. Remember to distinguish between hard bounces and soft bounces. Hard bounces may indicate that the address from which you are sending may have been blocked or the subscriber’s address no longer exists. Soft bounces may indicate that the subscriber is out of the office.

Unsubscribe rate

When someone unsubscribes from your list it means that they have lost interest in your message. A high unsubscribe rate might also indicate poor list hygiene. If you send out a campaign to outdated contacts, your unsubscribe rate may begin to rise.

Unique opens

Open rates tell you if your subject lines are effective and compelling. However, this metric can be inaccurate. For example, many email clients will record an open if the email appears in the subscribers preview pane even if the subscriber has not read the email. Inaccurate opens can also register if the subscriber clicks to delete the email. To counter the effects of inaccurate recordings of open rates look at the amount of unique individuals who open your emails, regardless of how many opens are actually being recording. Although this KPI limits your open rates to individual subscribers, it provides a more accurate assessment of your emails’ performance.

Open to click rates

This KPI measures a higher quality of engagement than unique open rates by telling you how many of the people who opened your email (not just who received it) and clicked through to a landing page. Make sure to track individual links within each email to see which links produce more clicks.

Conversion rate

Conversion rates tell you how many people click through your email and depending on your goal, either register their email with you, download a trial product or place an order.

Price per email sent

This KPI measures how much money you earn per email. It is the most effective KPI on this list as it measures actual ROI. If you’re spending one dollar per email and earning two, you know you’re having a profitable campaign.

How do you move the needle on your email marketing KPIs?

Responsive design

It is time to optimise for touch screens. The 2013 holiday season saw more than half of email opens occur on mobile devices. And that number will continue to grow every year.

Because so many people are accessing emails on mobile devices, you have to start incorporating responsive design into your emails. Find yourself a good designer or a good email marketing platform and start building responsive design into your main site, landing pages and emails.

Optimising for touch screens is recommended even if your software product is typically used on a desktop or laptop. Why? Let’s remember that many customers don’t convert on the first visit. Customers are busy conducting their own independent research and visits to your site and reading your emails are part of that research. If those site visits or those emails occur on a tablet or phone and they aren’t ready for those viewers you may be herding potential customers to your competition.

Email send frequency

Another way to move the needle is to test sending frequency. According to ExactTarget, the best practice is to let the reader decide by offering them a few choices about the send frequency. LinkedIn group emails are a good example of this.

LinkedIn allows users to set their own email send frequency:

The other option is to test sending frequency to see which frequencies have the greatest impact on your KPIs. Also test frequency against how engaged a subscriber is. If a reader never opens the email, opens but does not click or clicks but does not convert, consider resending it at different times.

Subject lines

Another way to move the needle is test subject lines with personalisation and include users’ names in the subject line or body of the email. Counter intuitively, according to an email marketing benchmark report from eMarketer published in 2013, shorter subject lines had higher open rates, but longer ones had higher click rates.


Monitor your email marketing KPIs like unique open rate, open-to-click rate and price-per-email carefully. Use your data to create a baseline of performance and then work to move the needle positively by optimising and testing how your emails look and how frequently you send them.