The popular photo-sharing app Instagram introduced on Thursday a messaging service that would let users send private photos and videos to their friends directly.
Kevin Systrom, a founder and the chief executive of the company, introduced Instagram Direct at an event in Manhattan.
“For us, communication is very core,” he said. “It’s not about photography necessarily.”
Mr. Systrom said that the feature is meant to let people start a private conversation around a particular photograph or video.
With the new service, users can share their images and videos with 15 or fewer friends at one time, instead of having to send the message to all their followers. The direct messages can be sent only to people who follow each other on the service.
“The whole idea of this feature is to take moments and send them,” said Mr. Systrom.
He said he envisions the service as being particularly useful to families, or to teachers who want to share with all the students in a class.
He also said that brands and advertisers would be able to interact with their followers using the new feature by inviting them to submit photos for a contest, for example.
“It’s not about spamming everyone you know,” he said. “It’s about sharing a moment with your friends.”
The introduction of Instagram Direct, available for iPhone and Android users, comes at a time when private messaging services like Snapchat and WhatsApp are rising in popularity among mobile users.
Private messaging has become big business overseas, including services like Line and KakaoTalk. And this week, Twitter introduced a new feature that lets users send photos privately to their friends.
“The amount of time that consumers spend within these apps is phenomenal,” said Julie Ask, an analyst with Forrester Research. “And they are only becoming more popular.”
Facebook, which bought Instagram in 2012 for $1 billion, has been trying to introduce a stand-alone messaging service for years with little success.
The company threw its weight behind a version of its social networking site for some mobile phones, Facebook Home, that included a feature called Chat Heads. But the service did not gain traction with users.
Facebook also has a messaging service called Messenger that has been met with lukewarm enthusiasm from users.
Most recently, the company tried to acquire Snapchat, the popular messaging service, for billions of dollars, but Snapchat turned down the offer.
Ms. Ask cited a recent report from a firm called Mobidia that showed Kakao users spent 200 minutes a week on the application. By comparison, those who used Facebook’s Messenger spent around 30 minutes a week in the application.
Brian Blau, an analyst at Gartner, suggested that Facebook was having difficulty figuring out which new services and features it should focus on as it moves forward.
“They aren’t doing poorly by any account, but they do seem to be struggling to figure out what to do next,” he said.
Instagram has had no problem attracting new users and keeping them entertained.
The company recently said it had more than 150 million users and billions of photos uploaded to the service. Most recently, the service has been slowly rolling out advertisements that it hopes will help the service generate revenue.
A private messaging service could bolster those efforts, simply as a way to “draw people into the app for more minutes and figure out how to monetize that,” Ms. Ask said.
In the United States, private messaging has yet to catch on the way it has overseas. Text messaging and iMessage — the messaging service built into Apple devices — is largely seen as sufficient.
While “the rest of the world is thinking about instant messaging, here it’s still something you did on your computer through AOL,” Ms. Ask said, referring to the United States.
