Testing is an essential in email marketing. Unless you test and test again you will not only fail to realise the full potential of any campaign but you will also lose a lot of ground to your competition. It is easy enough to ensure that your tests give accurate and useful data.

The most common tested facet of a marketing email is the Subject Line so we will stick to that. The probability is that changes here can directly effect the open rates, and we'd all like improvements there. However, blaming everything on just one aspect ignores the reality of consumer response. 

The fact is that email marketing does not exist in a vacuum. Outside influences can have a major influence. The timing of your email might have coincided with something of interest in the news such as  Attenborough's death. This was enough to affect anyone’s concentration for half an hour or so. Open rates might have suffered in consequence.

Or it could be that your last offer was well received and there's nothing like success to make subscribers receptive. So you can appreciate that a sudden boost in your open rates might not be down to the new impactive style of your Subject Line. There is, though, a simple way of eliminating the influence of variables.

For best results have a reason for running the test, such as no increase in open rates. However, a wild stab in the dark can sometimes be useful, as TV weather forecasters prove on occasion.

Let us say that you will try adding the forename to the Subject Line. Form an email marketing list of those to whom you will aim the campaign and then, being as random as you can, further divide the list, leaving a main section and a smaller one that is big enough to be dependable.

When you get the returns, if the smaller test group has a significantly higher open rate then you know that the change is a positive. It can be useful to test the change again at the next campaign, perhaps by splitting the list 50:50, just to ensure that novelty was not a factor.

There, I said it was easy.

With WizEmail you can automatically a/b split test your campaign content and/or subject lines with just a couple of clicks – Wiz will even send the winning campaign to the remainder of your data based on opens or clicks – clever little WizBots!