There are now 600 million people using Facebook’s chat application, Messenger, each month. At its F8 developers conference in San Francisco on Wednesday, the social network sought to bring a new member into the conversation: businesses.

Messenger is one of several standalone consumer-facing apps in Facebook’s portfolio, which now includes Instagram (photo-sharing) and WhatsApp (mobile chat). It’s one of the company’s most widely used products and one that has probably evolved the most in the last 12 months. Last year, Facebook split Messenger from its core Facebook mobile app. Mark Zuckerberg, Facebook’s chief executive, also appointed a new executive to lead the effort: former PayPal CEO David Marcus.

The biggest strategic shift for Facebook FB has been creating a family of apps for its users, Zuckerberg said on Wednesday, rather than shove ever more features into its namesake app. Messenger has matured into a multipurpose tool—users use it to dispatch messages, photos, and videos between them—that functions as the social fabric that connects users on the Facebook network. Zuckerberg and his team are betting that people want to use Messenger for all kinds of transactions—as a conduit to call people, for example, or send money. And, interestingly, as an inbox to connect directly with businesses.

Facebook Messenger for Business conversation
A business conversation using Facebook Messenger.Courtesy: Facebook

Facebook seems to believe that communication between businesses and consumers is fundamentally broken. In an e-commerce purchase, for example, the buyer is typically sent multiple emails—a receipt, a shipment confirmation, updates along the way. Often the buyer must log-in to the e-commerce site in question to access this information. And all of those interactions lack any real, natural communication, says Marcus.

“Commerce is conversational,” he said, speaking to software developers at the Fort Mason Center. It is more natural, he maintained, for businesses to converse with customers rather than broadcast to them. Messenger fits the bill.

Facebook used two launch partners—clothing site Everlane and mom-focused deals site Zulily—to show off the dynamic. Everlane incorporated Facebook’s services in its checkout page to allow consumers to opt to receive updates after making a purchase. From there, a mobile push notification and an opportunity to continue the conversation—from gleaning shipping information from UPS to modifying an order or purchasing another good—within the Messenger app. (Businesses see a customer service portal powered by Zendesk.)

Engaging the buyer at the point of sale was purposeful, Marcus said, because there is a high probability at that moment that the user is willing to interact with the brand. “It’s reintroducing personal back to shopping,” he said. “This is about creating rich content and interactions between people and businesses. You could imagine that in the future, a customer could have have multiple threads open with businesses that you care about, and you could transact and buy things.”

You can start to see the opportunity that Facebook detects: hotel confirmations, flight updates, bank account alerts, all within Messenger. For now, Facebook is targeting partnerships with larger businesses, says Marcus, because their customer feedback tends to be faster and more consistent.

You can also smell a little fear. Tencent’s WeChat app has seen much success integrating commerce into its own messaging app—for example, it launched the ability to order taxis through its messaging app; within a month, users booked 21 million cab rides through WeChat—and Facebook wants to keep up, if not stay ahead. (Fast-growing Snapchat has also adopted a like-minded strategy.) Hiring Marcus, who founded the mobile payments company Zong, certainly helps.

When asked if payments are the next step, Marcus maintained: “We don’t want to build a payments business but we need to reduce friction, so we will do what we need to do to fix that problem.”

But the bigger question is whether people want to engage with businesses in the same place where they chat with their friends. For Marcus and Facebook, the quality of the experience will be key. “If you want to change people’s habits, you need to provide them with something that is meaningfully better than what they have,” he said. If Facebook has its way, that will be Messenger.

For Fortune’s complete coverage of Facebook’s F8 conference, read:

Why Facebook’s Parse news is a big deal for the Internet of things

Facebook’s F8 developers conference by the numbers

With embedded videos, Facebook takes aim at YouTube

Facebook’s app-building platform Parse will expand to ‘Internet of things’

Facebook debuts Messenger Platform, will support third-party apps

Facebook will support ‘spherical videos’ in News Feed