There is a good reason why email is one of the most popular direct response advertising tools for most digital marketers. It is easy to set up, scales fast, delivers return on investment and can be very very effective. Like many other digital channels, one of email marketing's strengths is in how easy it is to track, and how effective it can become with a little applied analytics and analysis. Like so much other data driven activity, the trick is to know what to look at.

Even before you start to look at the information that is available on the users once they arrive on your site, Most mail programs and provides will already be tracking a number of metrics. The most commonly reported by most email providers are:

Bounce Rate
The percentage of emails sent that 'bounce' or could not be delivered. Broadly speaking there are two kinds: hard bounces and soft bounces. A soft bounce is generally a temporary issue, like a server issue or a full inbox. There is a chance that the email may make it through or be resent. A hard bounce is permanent. It could be from a dead or incorrectly entered email address. These email addresses should be scrubbed from your list. In fact some email marketing providers will do this for you.

Deliverability is how much you can count on an email you send actually hitting your recipient's inbox. Generally if your deliverability is poor you will need to look at the health of your list, and possibly even the tools or services you are using to send your mail. Many things can affect this, including send rates, IP addresses, content and getting flagged as spam or junk.

Email Open Rate
Open rate has been around for a while as a metric, though it is falling into disuse. One of the main reasons is how it is tracked. Opened emails are often tracked through loading a tracking pixel. Many email interfaces disable image loading. Consequently the numbers are not all that accurate.

Click Through Rate
For most marketing objectives, it isn't enough that the user opened the email, generally an advertiser would like them to do something. Usually this means clicking a link. Click through rate is one of the most important metrics for direct response campaigns, only beaten by conversions and ROI.

Shares and forwards
Wouldn't it be great if the recipient not only opened the email and clicked on a click, but shared it with their friends too? It would be even better if you knew which emails were more likely to inspire this. From branding campaigns to community building and finally direct response, tracking shares and forwards is a useful metric to track.

Unsubscribe rates track how many of your list members unsubscribe. At first glance this would appear to be a very important metric. And it is. Unfortunately user behaviour makes it hard to track. Users are just as likely to mark the email as spam, junk mail or just filter them. Like open rate, it would be a great piece of information to know, it is just a shame it isn't so easy to track.

Most email marketing providers won't be able to track this for you. This does not mean it isn't important though. At the end of the day, if you are using email to market, you want the recipients to do something. This could be anything from enquiry, conduct a search on your site through to handing money over.

The information you need to monitor the performance of an email campaign can be loosely divided into two groups: list health and performance. List health is vital if you plan on doing this over a period of time with the same list. As mentioned before, the quality of the email addresses you collect and the methods and suppliers you use to distribute them can be vital to getting some kind of return.

List Health

Fortunately most decent email marketing services will do most of the heavy lifting for you in this area. This does not mean you shouldn't be paying attention.

For monitoring list health there are really only two metrics that matter to a digital marketer, Bounce Rate and Deliverability. While most of the technical factors that can kill this will probably be out of your control, barring your choice in email marketing software or platform, there are a few things you can do.

  • Don't look like spam.
    Being flagged frequently as spam within major ISPs can be an issue. Some providers will remove addresses that flag you, and this is a good thing.
  • Manage your bounce rate.
    If you are collecting emails, ensure the data you collect is correct and validated. Also ensure that addresses that hard bounce are removed.
  • Don't be spam.
    Seriously, just don't. Market to recipients that have opted in.

List Performance

There are many metrics you can use for this, and unfortunately some of the most useful sounding are not reliable. There are a few robust figures to track though, and these include click through rate, forward and share rate and conversions attributed back to the email.

Baring robust and effective cross channel attribution, click through rate is probably the most reliable measure of success, with conversion rate a very close second. Click through rate should be provided by the email marketing provider, and can vary in sophistication. Ideally you should be tracking per link. This makes it easy to identify calls to action and product that resonates with your audience.

Many email providers will take care of tracking the activity within the emails you send themselves. In most cases keeping an eye on what is happening once the recipient has reached your site is your responsibility. The most important thing for tracking how well an eDM has performance from your own data is making sure that you know who has landed on your site as a result of it. The most commonly used tool for this is Google's URL Builder, which lets you create URLs with campaign source, medium and name values attached.

In conjunction with your on site analytics, this will help you to close the loop between the information provided by your email marketing provider and your own website's performance.

Making it all work

Bringing it all together is not that hard, and there are many tools available that can make this ridiculously simple. Setting up a successful data driven email campaign can be very straightforward:

  • Build your list and verify email addresses collected. Ensure form inputs are validated, and ensure users are opted in.
  • Find a good email marketing provider who will manage bounce backs and unsubscribe functions and provide at least the essential reporting.
  • Monitor bounce backs and deliverability for list quality. Generally 95% delivery rate is expected.
  • Optimise for click through rate. Trial different subject lines to drive that almost untrackable open rate and more importantly try out different content and calls to action to improve click through rate from email to your site. Also experiment with sending at different times of the day and week.
  • Monitor the traffic arriving on your site for quality through pageviews per visit and bounce rate. Also keep an eye on the device mix, sending at different times might bring slightly different audiences using different devices.
  • And finally, are they doing what you want them to do once they are there? If not why not? Experiment with different landing pages and always keep an eye on how the business outcomes from this channel stack up against the costs.

There is a lot to monitor, and over time a lot that can be done with more information, but the core metrics in any direct response email campain will inevitably be: deliverabiltiy, click through rate and conversion. After all, you can't have conversions without traffic and you can't get the traffic if no-one sees the email.