Earlier this year, we excitedly announced support for emojis in subject lines. What can we say, we just love the little buds. But which emojis are people using? How are they being used? And is "emojis" even the plural of "emoji"?

It’s been a few months, and we’ve started to answer those questions. 214,000 campaigns have been sent with emojis in the subject line since we officially added support for them. Multiply that by the number of emojis used and emails sent for each of those campaigns, and it turns out we’ve delivered 1.4 billion emojis to people’s inboxes. Here’s a look at some of the trends we’ve seen. We’ll be using Apple emojis, but there are several variations for different platforms.

The solo all-stars

First, we took a look at the top 15 emojis we’ve seen since February. These ranks are based on the number of subject line appearances made by each emoji. A few are also dingbats or other special characters that have been supported in browsers for a while. The registered trademark emoji took the number one spot, followed by the big-eyed happy emoji, then a smiley with heart eyes. An actual heart and a more standard smiley round out the top 5.

The popular combinations

Single emojis are cool and all, but combining emojis is where you can really get creative. In fact, 31% of campaigns with emojis use more than one of them. We used Gephi and the Force Atlas 2 algorithm to map the network of which emojis are used together. In the map, emojis that are closer together are used together more frequently, and emojis that are larger are more popular pairing partners. After removing emojis and pairs that are infrequently used, this chart enables us to learn a lot about how people combine emojis. Click on the image for a hi-res version.

 

So, what does all of that mean? We noticed a few things:

• Emojis from the same category are often used together (food, faces, animals, weather, etc.).
• Within categories, similar items are closer. Within the food cluster, alcohol, entrees, and desserts each have their own cluster. Fruit is off to the side, which might indicate that it is used for, um, completely different reasons.
• Certain emojis connect other small groups. The plane connects earth, travel, and transportation. The heart connects love, fashion, and exclamations.
• The sunglasses guy is cool. Too cool, in fact, to hang out with the rest of the faces. He is in the middle, and is combined with a wide range of other emojis. We like 😎🐵.

We’ve had so much fun looking at this chart and learning new things. We even printed off a giant copy to hang in the office.

The future

This is really just the beginning. We don’t see a consistent positive or negative impact from using emojis at this point, but they’re still growing in popularity and stabilizing. In the meantime, we recommend using them to convey meaning rather than as a gimmick. As Allison said in our emoji announcement post: "With screen sizes getting smaller—and devices like the Apple watch on its way—senders of email need to be able to pack more information and emotion into shorter messages. Emojis are great at this. They’re fun and expressive, but they’re also compact."

For example, the emojis in "Pizza party this Saturday! 🍕🎉" help clarify what your email is actually about. (And I would definitely go to that party.) On the other hand, the emojis in "Springfield Elementary PTA Newsletter 🍕🎉" seem out of place, gimmicky, and confusing since they have nothing to do with the subject line.

You should also try our A/B testing tool to see how well they work with your audience. And if they do work, run with it! Sometimes pictures are better than words.