Facebook is preparing to push its new workplace product into a lot more cubicles.

Facebook at Work, a nearly identical version of the social network designed specifically for communicating with colleagues, has been in a closed beta since January. But that pilot program is ending, and the company will likely launch a freemium version of the interoffice network by the end of the year, said Julien Codorniou, head of Facebook at Work, during an interview with Re/code.

This product has been a long time coming. Facebook has been using a version of Facebook at Work internally for years, and reports first surfaced that it was building an office tool for other companies almost 15 months ago. When, exactly, Facebook will launch the product is still unclear. So, too, is whether or not it will be able to convince customers to forgo their existing office products, in some cases with years of archived messaging and documents stored on them.

But Facebook’s going to try. More than 100 companies are using Facebook at Work as part of the beta, which is still growing, said Codorniou. Many of those companies are just now starting to expand the product internally. Heineken, for example, has been testing the product with just 40 of its top executives, but plans to expand Facebook at Work to all 550 U.S. employees by the end of September. Linio, a Latin American e-commerce company, is expanding the product internally from 200 to 2,000 employees by the end of the month.

As expected, Facebook does hope to make a little money from the new product, but not with the ad-dominant approach it’s known for. Instead, businesses will start with the free version and pay for extra features or analytics associated with their accounts, said Codorniou.

What, exactly, will be free and what will cost money is “still being defined,” he added. It’s unclear how many employees, for example, each company will be able to onboard without paying up, or if they’ll be charged extra to create a large number of groups. Facebook may take an approach similar to Slack, which charges for things like archiving messages and extensive product support.

What is clear, though, is that Facebook is about to step on a few toes. Once Facebook at Work is live, Facebook will start to actively pitch the product through its platform partnerships team, which means it will be in direct competition with Slack and Microsoft, which owns Yammer. (With roughly $340 million in venture money, you can bet Slack won’t simply roll over, either.)

After speaking with a small handful of beta customers, it seems clear that “familiarity” will be one of Facebook’s key selling points. Many people (okay, most people) already know how to use Facebook.

“If somebody comes into the company, they know how to use this tool from day one,” explained Ryan Holmes, CEO of Hootsuite, which is part of the beta group. “So training cost is zero. That’s important.”

That familiarity could also be one of Facebook’s biggest sticking points with possible customers. On the desktop, users are able to toggle between their professional and personal Facebook accounts (Facebook at Work has its own standalone app on mobile). Facebook will need to convince employers that green-lighting Facebook use among the staff won’t result in a loss of productivity.

So far, that doesn’t seem to be a concern.

“We’re a modern company,” said José María Pertusa, CMO at Linio. “We actually expect them to use social media. That’s the way we acquire most of our customers anyway.”

Added Holmes: “It’s unrealistic that organizations try to lock people out of social. It’s like telling people that they can’t have their own personal phone[s], and I think that’s how millennials are perceiving that.”