The Best Formula for Writing Subject Lines

1. "Innocent" words to avoid. You are most likely familiar with most of spam filters triggering words like "free", "make money", "buy", "order", "income" etc. But from our latest email tracking reports we made an unexpected discovery: such innocent words as "Help" and "Reminder" do not trigger anti-spam filters but affect negatively email open rate. Probably, these words do not express enough value or urgency and are not powerful enough to make the recipient open the email.

 

2. Personalization. Since the Subject line personalization has been adopted by spammers, it has no same effect as before. So, including the recipient's first name into the Subject doesn't significantly improve open rate. However, merging the mailing list name the recipient is subscribed to is possible. This will contribute to the sender recognition at least.

 

3. Repetitive Subject line. Email newsletters usually start with a good open rate that tend to go down with time. While it is important to establish recognition and branding of the email newsletter, the repetitive Subject line accelerates the drop in the open rate. Ideally the Subject of each new newsletter should have a combination of the brand recognition that repeats from email to email followed by a hint of what is inside this newsletter that is of interest.

 

4. Subject line length. The experience shows that the general rule to keep the Subject line to 50 characters or less works well. The exception is possible when you send the newsletter to highly targeted audiences, where the reader apparently wanted more information in the Subject line.

 

5. Promotional emails. Promotional messages used to not produce the same open rate as emails where the recipient has a high level of personal interest or looks for valuable and urgent information. With regards to promotional emails, the same rules apply. Keep the Subject straightforward and do not use ostentatiously promotional phrases, CAPS, or excessive exclamation marks in the Subject line. Consider using the Subject lines in the form of questions as they can perform better.

 

6. "Soft selling" vs. "hard selling". The difference between regular email newsletters and highly targeted promotional newsletters is in the goals they pursue. For example, regular email newsletters used to build relationships with your subscribers and are good for "soft-selling". Send them to slowly drive your subscribers at the purchase, or to make them create a good impression about your product or service. If your recipients subscribed for your newsletters, don’t expect them to express a high interest in the message with the subject line like "Don't Miss Our 50% Discount! Only 100 Coupons Available!" For regular email newsletters, keep the Subject lines simple and consistent.

 

From the other side, if people expressed the interest to receive promotions and offers from you, you have the right to use the "hard selling" Subject line. Only when marketers start sending "hard selling" emails to all their lists, this can cause troubles. The idea is not to mix different email lists and send promotional marketing messages only to those who opted in to receive such kinds of emails from you.

 

During the opt-in process always let the subscribers know what kinds of emails you will be sending them. If you allow the subscriber to choose the type of emails they want to receive, don't confuse the lists and respect the subscriber's choice. If you send a traditional newsletter, put the name of your company and a brief explanation of what's inside in your Subject line. If your message is a special promotion, say it in the Subject line.