When talking about how tortoises hold the secret to online success, I only talked about the total number of people on email lists. If you are a campaigner wanting to build up an email list to effectively communicate with residents in your area, that is an important number to have a sensible target for and to work towards.

But it’s only one of the three crucial email numbers.

The second is the open rate on your emails. Email open rate statistics are provided by most of the email management services available, and indeed it’s one of the main reasons for using such a service (along with the fact that the good ones sort out all the complicated technical work for you and also make it easy to send emails in both HTML and plain text versions). Mailchimp is the one that I recommend most of the time, as long as you are happy to put up with an overload of cute chimps. (Hey, it makes a change from the internet being infested / blessed with photos of cute kittens.)

Knowing roughly how many people open each of your emails is rather like knowing how many people return a residents’s survey. If you know the number you can experiment with the design, timing and content to see what gets the best response. If you don’t know the number, you are working blind and almost certainly not getting the most out of your communications.

Which leads on to the third crucial number … the click through rate. Knowing how many people click on the links in your email and which links they click on again is crucial to being able to produce emails that work effectively. It’s all too easy to think that hitting send on lots of emails means job done. It’s only job done if they are read and, where appropriate, links followed.

A simple practical example is my February Lib Dem newsletter, which featured a video clip about Lembit Opik a long way down the copy. Do people want video? Do people want long emails? A good open rate would tell me something about the subject line and the start of the email, but not the answer to those two. But the click through rate for the Lembit link gave the necessary extra information.

As it turned out, in fact that was the most clicked item in the newsletter, telling me that people were reading all the way down and that people like video (or at least that they  interested in Lembit). With a few more variations tried out in subsequent emails, I can build up a picture of what actually works (was it video or Lembit that did the trick?), all based on hard data.

So those are the three crucial numbers to look at when you are running email lists: the size of the list, the open rate and the click through rate. There are plenty of other statistics that you can look at and some are worth checking out now and again, such as how many people unsubscribed after a particular message or what proportion of your email addresses aren’t working. But there’s a risk with getting obsessed with tracking the numbers at the expense of doing something about growing the list and making the messages more effective. The trio I’ve mentioned will give you plenty of guidance to help achieve those bigger objectives.