In my last post, I presented a simple email campaign strategy that includes sending a text-only follow-up email to people who did not open the original email, and a multipart follow-up email with a special offer to those who did open it, 24 hours after the original send. While adding follow-up messages to email campaigns can produce some impressive results, it does raise a number of questions:

1. Won't recipients feel bombarded by receiving two email messages within 24 hours?

This is most unlikely. Recipients who did not open the original email probably did not register having received it. Therefore, when they receive the text-only follow-up email and if they register it, they will be engaging with the message for the first time. On the other hand, recipients who clicked on the original email are highly engaged with your message. They have visited your Web site, like your brand and like what you have to say. These recipients respond very well to further communication from you because they are already in a positive frame of mind about you. For more on this, see my previous article on email frequency.

2. Why is the open rate the same as the click-through rate on the text-only follow-up email?

We measure the open rate by inserting a 1x1 invisible tracking pixel in the HTML component of the email. If this pixel is downloaded, we classify the email as ‘opened', although a more accurate term would be ‘images downloaded'. With a text-only email, we can only record recipients who have clicked on links because there are no images. Therefore, the click-through rate will always be the same as the open rate on text-only email.

3. Why does the text-only email perform so well?

Because a text-only email looks good in the preview pane and has no images, it can be easily read and looks more like email sent by colleagues or friends instead of ‘marketing mail'. Text-only email is more favourably treated by spam filters, too, so it's less likely to be classified as junk.

4. Why don't more email marketers employ text-only 24-hour follow-up email to non-openers?

Many marketers think that once an email has been sent, it has been received by the recipient. Therefore, they believe that any lack of response is a proactive decision on behalf of the recipient that should be respected.

There are a few scenarios for which this is actually the case. However, the vast majority of non-responses to email are not the result of any action by recipients, but indicates instead that they simply have not seen the email. We all read email in different ways and at different speeds depending on what we are doing. If we are on the move or at a trade show, for example, we respond to email quickly and either ignore or delete non-essential email. On the other hand, if we are at our desks with 20 minutes of free time, we can give email more in-depth attention. So, in addition to the reasons mentioned under question #3, text-only follow-up email to non-openers has a good chance of being opened simply because it arrives at a different time in recipients' lives.

Another reason why marketers may not deploy this type of follow-up strategy is because it seems like a lot more time in content production work. The reality is that your text-only follow-up email is very quick to produce and test - the content is the same as the original message and there are no HTML rendering issues to worry about. The multipart HTML/text follow-up email to clickers may take a bit longer, but should only be a brief postcard-style email that reuses some of the imagery from the original email.

If you have other questions about incorporating follow-up messages into your email campaigns, feel free to ask them in the 'Comments' section below. And if you've already tried it, please share your experiences as well.