It’s all very well making sure that your email marketing campaigns are well-put together, carefully personalized and adhere to intricate workflows, but all of that matters little if you cannot measure their performance. That’s where key performance indicators (KPIs) come in.
Before you can measure those KPIs for email marketing, of course, you need to know what your goal is. Once you’ve figured that out, you can figure out the metrics you’ll need to monitor in order to measure your progress towards those goals.
Which leads us to the purpose of this article: what email marketing metrics should you be measuring, and for which purposes? Let’s take a look at the various email marketing KPIs that could be an important factor for you and your business.
You could make an argument that all other email marketing KPIs stem from your campaign’s delivery rate. After all, subscribers open 0% of emails that don’t get successfully delivered.
There are various reasons why an email might not get delivered. The simplest is that the email address, for one reason or another, simply doesn’t exist. Maybe someone signed up with a fake address, or perhaps they got a letter or digit wrong. Whatever the reason, such addresses are useless and need to be removed from your mailing list(s). See more about this below under ‘bounce rate’.
Another potential reason is that you’ve been blacklisted by an email provider. This is always a big problem that needs to be fixed as quickly as possible, no matter who the provider is. But when it’s a huge provider like Yahoo or Gmail, it’s a massive problem. One reason for being blacklisted like this is that you’re using a shared IP (as opposed to a dedicated one). This is a fairly easy one to fix: get a dedicated one!
As an aside, it’s important to realize that there’s a difference between an email getting delivered, and an email making it to a subscriber’s inbox. Many marketing emails are filtered out and simply end up collecting dust in the spam folder. That’s why some email marketing platforms like HubSpot are starting to use ‘inbox placement rate’ as a metric rather than deliverability.
Check our guide on the best platforms for email marketing, as well as great free tools you can use to level up your campaigns.
Strongly related to delivery rate, the bounce rate is a measure of emails that could not be successfully delivered.
There are two kinds of bounce. A ‘soft bounce’ results when an email is not delivered to a valid email address as the result of a temporary issue. Perhaps the recipient’s inbox is full, or there is an issue on the email provider’s end. Whatever the reason, a soft bounce is temporary and you won’t necessarily encounter that issue again.
Hard bounces are when emails are not delivered because the email address doesn’t exist. We mentioned this phenomenon above, and as above it’s crucial that you remove any email addresses from your lists that are producing hard bounces. They’re a key metric used by ISPs to determine your company’s overall reputation; the more hard bounces you have, the worse it is for that reputation.
So your email’s hit the subscriber’s inbox – congratulations! Now you simply need to have them open it. This is not as easy as it sounds; how many people leave their inbox full to overflowing with unopened emails? And which emails are the least likely to be opened? That’s right – marketing emails.
Desirable open rates vary from industry to industry, so it’s a good idea to take a look at what’s typical for your industry. The tech industry, for instance, averages an open rate of only 19.01%, while child care services have a whopping 42.60% open rate.
Clickthrough Rate (CTR)
Clickthrough rate – or CTR – might be the single most important metric for most email marketers. It’s probably the easiest metric to track on a daily basis, and it gives you a quick idea of how each individual email has done.
What’s more, CTRs play an important part in A/B testing, as they’re a quick and easy way to ascertain which of two given approaches nets you more clicks.
CTRs are invariably seen as important and valuable by email marketers. They immediately give you feedback about how interesting and engaging your email is – after all, nobody ever clicked on a link in an email because they weren’t interested.
Research suggests that the optimal clickthrough rate is between 6-7%. Anything more is unrealistic; anything less than that, conversely, means that your campaigns are underperforming.
Clicks By Link Or URL
A high CTR might initially seem impressive, but what if 60% of those clicks are subscribers reaching for the “unsubscribe” button?
This is, one would hope, not the case. But it’s still a good idea to find out which links within your emails are getting clicked on – and why. Are subscribers clicking your call to action, or are they clicking on an unrelated link earlier in the email? If so, why?
This email marketing KPI can give you important feedback on how the flow of your email is working, and what aspects of it you need to tweak. To return to the previous example: if a high volume of subscribers are clicking on a link early in your email that isn’t your CTA, then perhaps your CTA needs to take the place of that link, and the original linked either moved, or done away with altogether.
Whatever information you get from clicks by link is, in any event, bound to be useful to figuring out how you’re going to structure future campaigns.
Having a subscriber click through on your call to action (CTA) is only half the battle. Your CTA, after all, is there for a reason – to get the subscriber to do something. That might be purchasing a product, providing updated contact details, completing a survey, or any other number of things. The point is that it’s the desired outcome of the subscriber interacting with the CTA.
The conversion rate measures how many subscribers complete that desired action. If your link was to a survey you wanted the subscriber to complete, then every person who completed that survey would be considered as a conversion.
Your defined conversion should always be tied to the CTA contained within your emails in order for it to be a valuable metric. It’s also useful to be able to figure out where different clicks are coming from, which you can do with custom URLs such as those offered by email marketing platforms like HubSpot.
Your unsubscribe rate is exactly what it sounds like – how many subscribers have become ex-subscribers following an email campaign.
This is an extremely important email marketing KPI, and one that is neglected at your peril. There are a number of lessons that can be taken from your unsubscribe rate; if it’s low, then your emails aren’t being reported as spam, and not many subscribers are reaching for that unsubscribe button.
Conversely, if it’s high, then it could be you have a number of subscribers that simply aren’t that interested in your emails anymore, for whatever reason. This isn’t necessarily a bad thing; such subscribers were not going to contribute to a healthy open or CTR rate in any event, and so by removing themselves from the equation, they’ve likely improved the health of your mailing list.
Nevertheless, the ideal outcome is that you have a low unsubscribe rate because people want to receive your emails. Segmentation of your lists with software like Really Simple Systems is a great way to ensure that people keep wanting to receive your emails. Experiment with segmenting your lists by demographic, purchase history, and other metrics to minimize your unsubscribe rate.
Are your subscribers champing at the bit for your monthly newsletter, opening it the second it hits their inbox? Or is it languishing at the bottom of their unopened emails, gathering dust for days or weeks before they open it out of idle boredom?
The gap between a subscriber receiving an email and opening it is called the “event lag”. It can be useful in measuring how effective your subject line and preview text is; the more effective and eye-catching these are, the more likely you are to have a low event lag. It’s therefore a crucial email marketing analytic for those looking to improve these key factors.
List Growth/Decay Rate
This metric measures how much your mailing lists are growing – or, conversely, how much they’re shrinking (decay rate). Obviously the former is what you’re aiming for; you ideally want to increase your reach, expand your audience, and establish yourself as an authoritative and reputable industry voice to ISPs and email providers.
The plain and simple fact is that you’ll be facing an average list decay rate of about 23% percent yearly – which means you’ll lose almost a quarter of your subscribers. This isn’t due only to unsubscribes, but is also due to people abandoning or changing their email addresses. You can try to work on the former, but there’s nothing you can do about the latter.
The only way to fight list decay is by getting new subscribers on board. So-called ‘inbound’ marketing tactics like social media use and blogging can help to overcome that list decay rate, and ensure that your lists not only avoid decaying, but that they actually grow.
It’s a sad fact that some subscribers don’t simply unsubscribe from mailing lists – they report them as spam. This isn’t ideal and can cause your company headaches, but there is unfortunately not much you can do about it – aside from treat it as a useful KPI.
By monitoring spam report rates alongside unsubscribe rates, you can get an idea of whether or not you need to fix anything in your approach. If both spam reports and unsubscribe rates are high, then this is an indicator that there is a serious flaw in your campaigns that needs to be addressed.
Campaign Performance vs. Email Performance
Marketing emails seldom exist in a vacuum; they’re part of a larger marketing ecosystem, and it’s important to contextualize them as such. This is especially true when analyzing emails and campaigns as KPIs.
Some emails will be used across multiple campaigns, and should be analyzed independently of any given campaign to see how the email itself is performing. Analyzing it within the context of campaign A or B is less useful, because those campaigns may serve very different purposes.
On the other hand, it may be that you need email marketing analytics on a more macro scale – in which case, you’ll analyze things at the campaign level instead. Looking at the CTR for a campaign is very different to looking at the CTR for an individual email, and provides you with different feedback.
Ultimately, both are important for different reasons. Email marketing campaign KPIs help you adjust the whole, while individual email KPIs are more granular and are more useful for fine-tuning cogs in the machine, rather than overhauling the machine itself.
Forwarding/Social Sharing Rate
Beyond open and clickthrough rates, another email marketing KPI that’s gained increasing importance is the forward/share rate. Many email marketers now include links that enable subscribers to immediately share the email on their social media; measuring this data can be invaluable.
Forwarding emails is vanishingly rare in email marketing, so don’t expect to see too much of this going on. Following the proliferation of forwarded chain letters in the early days of the internet, many users have a hardwired distrust of any email that begins with “FW” – so don’t expect them to forward yours.
However, it’s more and more common for people to share interesting information via their social media. If they’re doing so with your emails, then it’s a sign that you’re creating emails that are relevant, interesting, and shareable. If not, then try to make sure that your next campaign does produce this kind of content.
It’s tempting to simply stick subscribers into a few subcategories: those who open, those who click through, those who unsubscribe, and those who do none of these things.
However, amongst the former two groups, there’s a little more nuance that can be used in your analytics. Some subscribers exhibit high levels of brand loyalty, and will consistently click through on every single email that you send. Other may only click through on (or open) your emails occasionally.
It’s worth analyzing this data and segmenting your subscribers accordingly. The former group are probably likely candidate for loyalty bonus emails. The latter group should probably be subject to further analysis: when are they opening your emails? What kind of links are they more or less likely to click through on? How can you exploit this data to increase their level of engagement?
Finally, you’re going to have some subscribers who are completely unengaged. They’re subscribed and they opted in, emails are being delivered, yet their open and clickthrough rate is consistently zero. Is it worth trying to re-engage this type of subscriber? Likely not.
In fact, by continuing to send emails to people who are not engaging at all (sometimes called “graymail”), you’re actually hurting the overall health of your mailing lists. Graymail is often flagged by email providers and sent straight to junk folders, meaning that while it’s been technically delivered, it will never get seen.
The best answer in this situation, then, is to cull your mailing lists. It sounds counter-intuitive to get rid of subscribers that are happy to receive your emails and haven’t unsubscribed, so why would you do this? Because a subscriber who isn’t engaging with your content at all is functionally identical to a non-subscriber. They’re worse, in fact; they hurt the health of your lists. So reach for that delete button and continue with people who engage with your emails.
Assessing which email marketing KPIs are valuable for your particular needs – and which can be safely disregarded – can be a very tricky balancing act. It very much depends on the needs of your business, the product or service that you’re marketing, and the nature of your subscriber base.
Making heads or tails of all of this can be overwhelming. But the good news is that there are a great many automated email marketing platforms out there that can help. With such a service it’s possible to automate a lot of responses to the KPIs that are most important to you.
Automated segmentation and workflows, for instance, can make sure that subscribers of varying demographics and levels of engagement receive the appropriate emails at the appropriate time. It’s also possible for providers like HubSpot and MailChimp to automatically manage your lists and purge dead email addresses or those not responding to your campaigns, taking a lot of the busywork out of managing email marketing.
In fact, with recent advances in AI tools that can assist with automated email marketing, it’s never been easier to manage and maintain your mailing lists as well as track your KPIs. All you need to do is find the tools that are right for you.