While Facebook would not disclose exact figures, it said Workplace - a rival to collaboration services like Slack, Salesforce, and Microsoft - has been a hit and that ranks of users have doubled in the past eight to 10 months.
"It is growing very fast," Workplace by Facebook vice president Julien Codorniou told AFP.
"We started with big companies, because that is where we found traction. It is a very good niche."
Workplace is a separate operation from Facebook's main social network and is intended as a platform to connect everyone in a company, from counter or warehouse workers to chief executives, according to Codorniou.
Workplace claimed that a differentiator from its competitors is that it connects all employees in businesses no matter their roles, even if their only computing device is a smartphone.
"That really resonates with a new generation," Codorniou said of Workplace's "democratic" nature.
"Millennials want to know who they work for and understand the culture of the company."
He cited cases of top company executives using Workplace to get feedback from workers at all levels, bringing a small company feel to big operations.
Workplace is rolled out to everyone in companies, which then pay $3 (roughly Rs. 222) monthly for each active user.
No 'Candy Crush'
The software-as-a-service business began as an internal collaboration platform used at Facebook and was launched as its own business in 2016.
Workplace is used by 30,000 companies and has its main office in London, according to Codorniou.
Interaction with the platform plays off how people use Facebook, and Workplace adopts innovations from the leading social network. But, it is billed as a completely separate product.
"This is coming from Facebook, but has nothing to do with Facebook," he said.
"You cannot play 'Candy Crush' on Workplace, but people ask. We just take what makes sense."
The conference was used to announce new Workplace features including a version of Facebook safety check designed as a way for companies to quickly determine the status and well-being of workers in event of disaster or tragedy.
Workplace also introduced the ability to have group voice or video chats with people routinely worked with outside a company.