Advice for Email Subject Lines

An email subject line can singularly determine if a recipient opens your email and engages or sends it straight into the trash. Despite the importance of a strong subject line, many people fail to understand the science behind creating an immediate sense of engagement on this front.

A recent study by Mailchimp found that, on average, emails are open between 15% and 25% depending on the industry the email is targeting.

So how do you circumvent the roadblock that occurs when an email enters into a potential client’s inbox?

Here is some advice about creating the perfect email subject lines from industry-leading publications that are focused on client engagement.

Generate A Call To Urgency

The team at has done a great job of giving direct advice for urgency. The goal here is to give a very short but effective call-to-action.

  • Formula: [Action] Now
  • Example: Open this right now

This type of email subject line feeds directly into our psychological need to not miss out on something or lose valuable savings when we fail to act now.

Provide Social Proof points to a “fundamental characteristic of humans” to examine the behaviors of others. You can improve click-through-rates on emails by leveraging individual success stories, familiar names, or highlight the reach of a product. Combining social proof with an action to accomplish the same goal can go a long way.

  • Formula: [Famous Person] Is Using This Technique [Action]
  • Example: Gary Vaynerchuk Is Using This Technique To Rapidly Grow Their Business

Words and phrases such as “rapidly, right now, and immediately” help to once again deliver a sense of urgency.

The Case Study Call-To-Action

CRM-leader Hubspot examined the most success emails from millions of customers and found a high-level of engagement when a case study model is employed.

The company points to a successful campaign from Docusign.

  • Formula: [Case Study Company] [Findings]
  • Example: Docusign: “What are our customers saying?”

The email in the case of Docusign focused on various case students that pushed customers towards purchasing the company’s product. Docusign shared findings within the email to highlight customer successes based on the company’s study of their emails.

Ultimately, a successful email subject line needs to stress a sense of urgency, provide social proof of efficacy, and deliver a direct line of collectible data that a reader can examine. Think of your email subject line as a strong headline for a publication and you’ll be off to a great start.