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Nexxus Blog

Crafting Compelling Subject Lines

12 May 2015

Without an effective subject, even the best email will go unread. Whether crafting an email headline or a blog post title, a compelling subject line is of utmost importance.

Effective subject lines are created by testing a variety of messaging, analyzing campaigns, and optimizing to drive results. To break through inbox clutter, headlines must be concise, engaging and should encourage a call to action.


Life science marketers can test a variety of messages to learn what will resonate best with their audience. Segmented campaigns can help test different messaging, determine which subject lines are most powerful and encourage click through. In addition to traditional market research on your messaging, make sure you incorporate A/B testing of subject lines as a standard practice in your email programs. (Learn more about A/B testing best practices by clicking here.)

What Makes A Subject Line Effective?

Here are a few things to keep in mind when coming up with your subject line:

- Be useful and specific, make sure it’s relevant to your audience.

- For an ongoing series, prefix the subject line with a consistent identifier.

- Keep it relatively short! 50 characters or less is ideal, except in cases where brand and generic name must be included.

- Be visually different – make the subject stand out visually by trying square brackets, sparing use of capitalization or quotes.

- Use timely topics that are top of mind, and use urgency only occasionally to point out deadlines.

- Use a call-to-action (CTA) by asking a question.

On the other hand, there are some things that have been shown to decrease the likelihood that an email will be opened, including:

- Making references to “you,” “your,” or “you’re,” “easy,” “how to,” or “free.”

- Adding positive superlatives (“best”, “always”).

- Using words that convey a sense of urgency (e.g., “need,” “now”).


With email campaigns, key metrics to optimize for include open-rates, click throughs, forwards, and unsubscribes. Once you know which subject lines are most effective, similar messaging and verbiage can be used in future campaigns to drive strong results.

In many ways, an email subject line may be the most important part of your message. It’s what will compel your audience to open that email (or not!). Through testing, analysis, and optimization of efforts, you can create effective subject lines.

For more information on how Nexxus Marketing can help life sciences marketers with multichannel delivery, contact us at or click here to visit our website.