Marketers seem to have finally found a way to get customers to open up their emails and text notifications: emojis.

Whether using a smiley face with hearts for eyes or a virtual gift box wrapped up, push notices with emojis are opened 254 percent more often than those without emojis, according to a study released on Tuesday, which was World Emoji Day. Emails with emojis are opened 66 percent more frequently than standard emails.

The report, from mobile engagement platform Leanplum, analyzed 300 million mobile messages — emails and push notifications — worldwide for a full year, starting June 1, 2017. Apps also benefit from emojis, decreasing uninstalls by 26 percent.

“When a person sees an emoji in a message, their brain lights up the same way as when they see a human face,” said Joyce Solano, Leanplum's senior vice president of global marketing, in an interview. “Emojis are great for conveying tones, facial expressions and emotions.”

While emoji use has exploded, it still has a way to run. Almost 30 percent of messages have at least one emoji, double the amount from the prior year. Leanplum said that 157 new emojis are on tap for release in the second half of the year.