Marketers delivering email messages to customers

Best Practices: Email Subject Lines for Energy Utilities

If an email lands in an inbox and nobody opens it, does it really make an impression? Of course not! No matter how much work you put into crafting an effective message, selecting the right image and optimizing your CTA, your email will not accomplish its goals if customers don’t open it.

Subject lines drive opens. And without opens, your marketing, communications and program promotions simply won’t make an impression with customers. In order to ensure success, here are Questline’s recommendations to boost open rates and increase engagement with your energy utility’s email campaigns.

Email subject lines should be clear and specific

An effective email subject line will catch the attention of the recipient and inspire them to open the message to learn more. The most reliable way to do this is to speak directly to the customer’s interests or concerns: How would opening the email benefit them?

  • Subject lines should be quick, clear and specific; the best length is 50 characters or fewer.
  • Use actionable language and active verbs.
  • Put important words at the beginning of the subject line; catch the customer’s attention immediately.
  • Be consistent: The subject line should match the message.

Promote program benefits

Program promotion emails have a benchmark open rate of 23.8%. Residential customers respond well to specific references to their situation; email subject lines with the words “you,” “your” and “about your” tend to exceed benchmark. The following best practices have also been shown to improve performance:

  • Include a promo code. Subject lines such as “Save XX when you use promo code XXXXX” tend to improve open rates as well as CTOR.
  • Mid-range incentives work best. Incentives of $1,000 or more underperform compared to $25 to $100 incentives.
  • “We’ll Pay Your Bill” incentives are high performers.
  • Thermostats and smart-home device giveaways are also top performers.
  • Conversely, subject lines with the word “free” do not perform as well.
  • Most subject lines with emojis also perform under the benchmark.

Engage customers every month with newsletters

Email newsletters are periodic in nature. Keeping this in mind, the most successful subject lines engage readers month after month. For example, include the name of the newsletter followed by a customized field, such as the lead article title: “Your Energy Newsletter: Custom article title.” Newsletters that follow this convention exceed the benchmark open rate by 25%.

Pick a winner with A/B testing

An important way to optimize email subject line performance with a particular audience is through A/B testing: Send two versions of a subject line to small sample group, measure open-rate and CTOR performance, then deliver the “winning” subject line to the remaining mailing list. Through the consistent use of A/B testing over time, an energy utility can narrow down very specific best practices for customer segments.

  • Is my sample size big enough? Typically 500 to 1,000 recipients is an effective sample size and will deliver statistically meaningful results.
  • How long should the test run for? More than 50% of opens and clicks happen within the first 6 hours after email delivery. However, to eliminate seasonal and day-of-week variables, it’s best to test for one full week before determining a winner.
  • Is there a clear winner? Depending on the sample size, a good rule of thumb is to look for a 25% to 35% performance variance in order to declare a clear winner.

Download Questline’s digital marketing tip sheet, “Best Practices: Email Subject Lines.”