The main difficulty in answering the “how much is too much” question is the fact that an email database contains people and what is too much for one person may be too little for another. The problem is compounded when you add relevance into the equation, because relevant and timely message are always welcome.

The key to optimising mailing frequency is to analyse customer behaviour rather than campaign performance. In other words, focus on the people and not the list.

Let’s say your monthly offer mailing has an average open rate of 25%, click rate of six% and generates £20,000. It would not be unreasonable to consider whether you could increase your revenue by sending out 2, 3 or even 4 campaigns a month. So which of these mailing frequency options is the right one?

The correct answer is all of them and none of them!

The problem with campaign based statistics like those in the example above is that they tend to make you base your decisions on averages. What you end up doing is trying to identify what the optimum mailing frequency is for the average person on your list.

What we have found here at Alchemy Worx is that when it comes to finding the balance between the need to maximise revenue and minimise email fatigue; it is vital to consider all behaviour not just the average.

If you crunch the numbers differently – as we do – what you will probably find is that hidden in the averages are a very small number of people doing most of the work.

Between 1 and 5% of the list open, click and buy almost every time they receive a message; in some cases they are responsible for as much as 20% of the revenue generated by that campaign.

40 – 60% of the list will interact with the offer mailing once or twice a year and 35 – 55% of the people on the list will not have opened or clicked, let alone bought off an email you sent in over a year; very few of these inactive people will ever open another message from you.

Armed with this understanding you could argue (relevance aside) the following:

• Too few - The first group is being under mailed and might actually appreciate being sent weekly offers

• Enough – The second group is probably be being sent about the right amount of messages, however it would be worth testing the impact of a higher frequency especially if the additional messages are lifecycle or event triggered messages.

• Too many – The third group is being mailed too much and a mailing frequency of zero might be appropriate

Relevance and timing have a huge impact on how an individual regards any given messaging frequency; getting this right (a topic in its own right) requires a deep understanding of customer profiles and the use of event triggers and lifecycle marketing techniques in your email programmes.

Don’t forget wherever possible let your customers decide by giving them the opportunity to choose the frequency that best suits them at sign-up and unsubscribe via preference centre.

Dela Quist is CEO of email marketing specialists Alchemy Worx Ltd and Chair of the Events and communications hub of The DMA Email Marketing Council

---