Meta Platforms is opening its WhatsApp messaging service to advertising. The company revealed that three ad modules will roll out gradually. The ads will be positioned under WhatsApp’s Updates tab, a section discreet from WhatsApp’s users’ message inboxes and private chats. The Updates tab is also the entry point to WhatsApp’s Status feature, which lets users share photos, videos and text that disappear after 24 hours, similar to Instagram Stories. Meta says the Updates tab gets 1.5 billion visitors per day. The company is also seeking to monetize WhatsApp’s Channels feature by offering paid subscriptions and promoted Channels.

Meta CEO Mark Zuckerberg “plans to make WhatsApp a big business,” reports CNBC, noting that WhatsApp’s founders, who ran the company prior to Meta’s $19 billion acquisition in 2014, “shunned advertising,” as the platform’s privacy-conscious users may, too.

“Nothing changes about people’s personal chats, which remain end-to-end encrypted and are not used for ads,” Meta assured users in a news post.

“Already, Meta allows advertisers to run so-called click-to-message ads on Facebook and Instagram that steer users to WhatsApp where they can directly engage with businesses,” CNBC writes, quoting Zuckerberg telling analysts in April that “messaging between brands and consumers ‘should be the next pillar of our business.’”

At that time, Zuckerberg told analysts that WhatsApp currently has more than 3 billion monthly users, of which more than 100 million are in the U.S., where he said the app continues “growing quickly,” per CNBC.

Meta says “subscriptions, promotions and ads will appear only on the Updates tab, away from your personal chats,” though the Channels, which are personal in nature, will have search advertising, according to CNBC.

The three ad modules will roll out gradually. “While scrolling through friends’ status updates, users will see status updates from advertisers and can send a message to the company about the offering that it is promoting,” Ars Technica says of the Status tab ads.

With the Promoted Channels, Meta “is allowing advertisers to charge users a monthly fee in order to ‘receive exclusive updates,’” Ars Technica writes, explaining that “people could subscribe to a cooking Channel and request alerts for new recipes.”

Promoted Channels let admins increase their Channel’s search visibility for a fee, similar to how app stores and Google Search works.

Ars Technica reports that in deciding what ads to show to whom, “WhatsApp will leverage user information like their country code, age, their device’s language settings, and the user’s “general (not precise) location, like city or country.”

Meta posted a WhatsApp advertising FAQ that provides further details.