Before you begin, take some time to review your user profile. Who are they? What are they likely doing when they receive your transactional or notification email? How do they feel at that moment? What will prompt them to open your message now, instead of one of many other unopened emails?

Keep the answers to those questions in mind as you read these 5 tips to help you write effective subject lines.

Personalization is key, but make sure it’s the right kind.

It’s standard operating practice these days to put someone’s name in the subject line, but there’s plenty of other information you can include. Advanced techniques like natural language processing can help optimize subject lines based on user behavior and preferences. Just make sure you don’t overload the subject line.

Here are 7 ways you can insert personalization:

1. Who they are (name insertion is key, but don’t stop there)

2. Who they care about, such as friends and co-workers (such as the emails Facebook and LinkedIn send to you)

3. What they did (not just purchases but also browsing and other activity)

4. What they didn’t do (abandoning their online cart or not completing a profile)

5. What others did in reaction to their activity (responses to status updates, or the number of reactions to a product review)

6. What they have (account balances, or care or service instructions for a purchased product)

7. Where they are (geolocation-based messaging, such as letting a customer know about a sale at their local store) For example: [FIRST NAME], [#] people replied to your comment – see what they said

Yes, you can use an emoji (or two), but remember the word “sparingly.”

An emoji can add a splash of fun to a subject line, especially if it’s something lighthearted, but you probably don’t want to use more than two emojis in a subject line. For example:
Wondering who commented on your review? ?

Just remember that emojis render differently across various email platforms, so make sure you double-check your choices with a resource like Emojipedia.

Be funny, or memorable, or just fun.

This is another potential minefield, but if you approach it the right way, your email could be the subject of a viral “Check out this great email I received” post on social media. At the very least, it can bump up your open rates.

If you’re not sure about turning your subject line into a mini stand-up routine, try making an impression with a memorable quote, fun fact, or pop culture reference. There are plenty of places online where you can find quotes and facts, and we assume you, or someone in your office, know a bit about pop culture.

For example: Dolphins still know each other 20 years later — don’t wait 20 years to reply to [USER NAME]’s post

Create a sense of urgency with a deadline.

You can let someone know that the items they’ve saved in their cart have low quantities on hand, or that those items will be cleared from their cart if they don’t purchase then by a certain date. Or that an offer they signed up for is about to expire. For example:

For example: Uh oh: Your cart will be empty – and lonely – if you don’t buy what’s in it by [DAY]

Try an old-fashioned straightforward approach.

If you feel like everyone else is trying really hard to stand out by shoving personalization, emojis, jokes, and deadlines into their subject lines (subscribing to your competitors’ services and using their apps can help you stay abreast of trends), maybe you should simply tell it like it is.

For example: Here’s your receipt for [ITEM] – thanks for your purchase!