More than 75% of emails remain unopened. Here’s what you can do about the ones you send.
Written by
Jasmine Handa

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More than 75% of emails remain unopened. Here’s what you can do about the ones you send.

Published : March 14, 2023
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The data isn’t surprising since users are constantly bombarded with information in their digital spaces. WhatsApp messages, Tweets, LinkedIn posts, Insta shares, Facebook posts, Snapchat clicks —the influx is endless. And email is just one of them.

For email marketers, this isn’t great news. What’s the point of crafting an excellent email if it is unread?

Well, there are some proven tactics that encourage email opens in inboxes. One of the most effective ones is SLO (SUBJECT LINE OPTIMIZATION).

In this article, we offer a 101 on SLO and lead you through how it can amp up your email marketing efforts.

What is SLO?

SLO refers to the process of creating, testing, tweaking, and streamlining email subject lines to achieve maximum open rates. SLO allows marketers to identify which subject lines or specific elements in multiple subject lines create the most resonance with target audiences.

In other words, which subject lines get people to open the email?

In its most effective form, SLO personalizes the subject lines with user names. It is based on insights from users’ purchase history, past browsing patterns, product preferences, important days, stages of the customer journey, and several other relevant data points. The goal of the exercise is to catch the user’s eye and convince them that the email is worth reading.

SLO has proved to be highly beneficial in improving engagement and click-through rates, and subscriber affinity, which directly boosts sales numbers and marketing ROI. Smart SLO also reduces unsubscribe requests by creating better customer responses and positive brand impressions.

SLO best practices

A few best practices when writing your email subject lines are:

  • Keep the subject line short.

The Email Benchmark Report 2022 – a study of 100 billion emails recommends keeping your subject lines short: it is what the mobile-dominant world prefers. Any subject line that goes over 36 characters in length (including the spaces) gets automatically truncated on the mobile display. The viewer only sees a broken view of your subject line – cut off at the 37th character – leading to incomplete and unappealing information.

The optimum subject line length that has received the highest open rates is 30-35 characters with spaces.

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  • Avoid punctuation marks as far as possible.

It makes the subject line simpler and more readable. If you must use punctuation, use commas. Studies show this can improve email performance, especially if you use three commas to indicate a list of items or brands.

  • Use industry-specific as well as general keywords.

For example, the keyword “discount” has been shown to result in increased open rates. Similarly, subject lines that include brand names or convey FOMO (FEAR OF MISSING OUT) also attract users with greater frequency.

  • Leverage the effect of personalization. 

Address users by their first name and/or include information based on their purchase history or past interactions. Tweak the subject line so that it seems to appeal directly to the specific recipient.

  • Invoke emotions in email recipients.

Use words like “mouth-watering” when talking about food or “head-turning” when talking about fashion. Get people to imagine the outcome you want in a positive way.

You can even experiment with negative words or terms combined with a witty twist to get more attention. Here’s an example: “Get lost. In the big bonanza summer sale.”

  • Feel free to use emojis, but keep it down to three.

Studies have shown that subject lines with more than three emojis impact email performance negatively. 

While the above pointers will help you generally optimize for millions of users, getting it correct across locations, gender identities, cultures, and preferences is beyond any human’s (or a human team’s) ability. 

In a consistently competitive market where a user’s attention is gold, you need AI.

Netcore Cloud leverages SLO with AI

The Netcore Cloud  AI-powered SLO generation tool enables marketers to experiment and determine the most effective subject line for each campaign. Here’s a brief look into what our tool offers:

  • Predicting estimated email open rate for a subject line: By leveraging ML-supervised algorithms, our tool can estimate the open rate of a campaign email based on the specific subject line and the time frame within which it is sent. It is ideal for marketers to compare subject lines and decide on ones with the maximum potential to deliver higher open rates.
  • Displaying the five historically best and worst performing lines: The tool matches your entered subject line with all previous similar lines (based on similarity score) and picks out the five best (based on open rate) and worst performing lines (based on spam score).
  • Predicting inboxing quality of the subject line: The tool analyzes each subject line and gauges how likely the campaign email is to go to the recipient’s spam folder. Based on this, it will suggest whether the mail has a “High” or “Low” chance of inboxing. Marketers can use the spam analyzer to ensure that each campaign enjoys the highest possible reach.
  • Sentiment analysis of the audience: The tool will gauge the sentiment conveyed with each subject line. As it turns out, people respond more to subject lines featuring extreme sentiments, such as lines with words like “MADNESS,” “URGENT,” “LOSE,” etc.  The tool will highlight the sentiment associated with each line so you can tweak it to generate more attention and intrigue.
  • Word and metatag suggestions: Metatags are predefined lists of names, emojis, or character combinations (hashtags, location, client name) usually found in subject lines.  Our tool contains a repository of metatags that can impact inboxing and open rates. Marketers can pick from these to enhance their subject lines.

In conclusion

As mentioned before, the most perfectly crafted email will be useless if it is not opened. And open rates depend a lot on the email’s subject line.

Use Netcore Cloud’s decades-long experience and state-of-the-art AI technology to create subject lines that give you the highest possible engagement and ROI. Allow your email campaigns to generate results that go from “good” to “outstanding” and tap the full potential of email marketing.

Optimize your subject lines with AI and give your campaign emails the adrenaline boost they need to skyrocket their ROI.

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