Facebook Messenger remains the most popular chat app in the world with WhatsApp — which is expected to open its Business API to large enterprises — a close second.

But don’t forget that Facebook owns a third popular social chat app. Instagram is becoming the de facto way for people of a certain age to keep in touch, whether through sharing photos, video, or direct messaging. Naturally, that means businesses want in on the party.

Follow the green dot 💚

Instagram announced a new feature last week: a green dot that indicates when a user is active on the app. As Business Insider points out, the feature is Instagram’s latest effort to highlight the app’s messaging features.

Last month Instagram launched group video calls, allowing users to video chat with up to four users in direct message threads. Business Insider analyst Peter Sarnoff writes that Facebook’s aim is to make Instagram the “go-to-platform through which users communicate,” which will open the door to business messaging:

As users become accustomed to using Instagram as a communication tool, the app will likely begin adding business-to-consumer (B2C) services, a roadmap used for Messenger.

10X? Make that 100X! 💸

When Facebook purchased Instagram for $1 billion in 2012, the internet groaned. The app had no revenue, no business model and it wasn’t clear if its hipster users would tolerate ads in their artfully-curated feeds. Now Instagram’s worth $100 billion, according to Bloomberg.

Over the past half-decade Instagram has become a marketing juggernaut for brands, spawning a new generation of social media “influencers” who are paid handsomely to endorse products. The app could account for 16% of Facebook’s revenue this year, according to Bloomberg, and exceed 2 billion users over the next five years.

As you know, Apple and Google are both entering the business messaging fray. A new cohort of brands just Apple Business Chat and T-Mobile started rolling out support for RCS, the next-generation texting standard backed by Google.

Now Facebook has the opportunity to add yet another contender to the mix.