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The customised email subject line

Here’s an interesting little case study that came from a reader. They told me: “I took over running of our company’s customer email newsletter, which was well-established. Its open rate was consistent, but not that high. I decided to improve this by changing the subject line of each edition, which had previously always been the same (“News from…”) to a headline highlighting the main story.

“Disappointingly, the open rate barely moved. After a few editions, however, we decided to look at the open patterns on an individual reader basis. We found that many recipients seemed to open editions irregularly. Did this mean anything? We weren’t sure. However, when we went back to examine earlier editions where the subject line had always been the same, we found that this irregularity hadn’t been as pronounced. The emails had been opened by a smaller number of people, but more frequently.

“What was going on? It didn’t take long to guess. Back when the subject line was always the same, the email appealed to a consistent group of core ‘fans’. After we began to highlight what was in each issue, some of these fell away, but were replaced by recipients who were attracted by the individual subject line.”

I agree that this was surely what was happening. Some of the recipients who’d previously been prepared to open every email (even though the subject line didn’t reveal what was in the newsletter) now only opened editions where the subject line appealed. But other recipients who hadn’t been tempted by the old generic subject line suddenly started opening emails which looked like they had something of specific interest.

So now that our reader has discovered that the subject directly influences the chances of the email being opened, how can that information be put to work? Consistently great subject lines might be all that’s needed, but the key looks like it’s in the relevance. And for that, we need to write a subject line customised to each recipient, highlighting why they should open the email. Obviously that’s not possible on an individual basis, but if we can get data into the email system about what ought to interest each recipient, we can at least start to group them and write separate headlines for each segment. Even putting the recipients into just two or three groups might make a big difference.

Note: I realise that some readers will already use CRM systems which have exactly this kind of thing built in as standard. But my experience is that surprisingly few businesses are using even this basic level of sophistication.