Email remains one of the most effective and versatile channels available to marketers.

One of its main strengths is the variety of goals that can be achieved through email, including sales, customer service or aftersales.

Each different campaign may have slightly different KPIs, but there are some that are universally applicable.

Here I’ll summarise some of the most important email KPIs that marketers need to be aware of – it’s for beginners, so experts should already be well versed in all of these.

And for further information on how to get more from your email campaigns, download Econsultancy’s Email Marketing Census Report 2014.

Open rate

The most basic measurement of email success and one that doesn’t actually reveal all that much, the open rate simply shows the proportion of recipients who opened your email.

One major flaw with this metric is that it’s generally tracked using an impression pixel, so if a subscriber’s email client doesn’t automatically download your images then it won’t register as an opened email.

Nonetheless, it’s worth tracking this metric over time for any major fluctuations or long-term trends, and for comparing the efficacy of different subject lines.

Marketers should also benchmark their efforts against other their industry peers.

Clickthrough rate

Another basic measure of email success, revealing the proportion of people who clicked on a link within an email.

Email service providers setup different tracking URLs for each CTA, allowing marketers to compare the efficacy of each link in driving clicks, as well as users’ subsequent on-site behaviour.

Click-to-open rate

This metric is more useful than a standard clickthrough rate as it shows the percentage of unique clicks compared to the number of unique opens.

It is therefore a more accurate indicator of how well your email content is performing.

Conversion rate

The conversion rate tells you how many people that clicked through your email went on to achieve a certain goal.

This doesn’t necessarily mean sales, it can refer to any action that is relevant for your business, such as a downloading a white paper or even booking a test drive.

By tracking this metric over time you can get a good idea of the type of content and creative that is most effective for your subscribers.

However it is obviously influenced by other factors such as design and your product offering, so it’s a good idea to compare the conversion rate from email against other marketing channels.

Price per email sent

Another important KPI as it tracks the actual ROI of your email marketing. There’s no use bragging about the £5 earned on average from each email sent if you’re spending £6 per email sent.

The price per email sent is essential for tracking the profitability of your campaigns.

Unsubscribe rate

It’s inevitable that email subscriber lists will decline over time as people grow tired of your marketing messages and decide to opt out forever more.

However the rate at which people opt out is impacted by the frequency, quality and relevance of email marketing, so it’s important to track this metric to ensure your messages aren’t repelling potential customers.

Industry data varies, but in general an unsubscribe rate of around 0.5% or lower is praiseworthy.

Bounce rate

The bounce rate refers to the number of emails that failed to deliver due to an invalid or non-existent email address.

This may not seem like a major problem, but in the eyes of internet service providers a high bounce rate is the hallmark of spammers.

Therefore you should carry out regular hygiene checks to remove invalid emails or you may end up being classified as a spammer.