Former Facebook Execs Raise $50 Million More for Latest Venture by Heather Clancy @FortuneMagazine March 30, 2016, 11:05 AM EDT E-mail Tweet Facebook Linkedin Share icons Collaboration software startup Asana, which counts Zappos and Uber among its biggest high-profile customers, has raised another $50 million in backing that more than doubles its last declared valuation, according to its two co-founders. Asana was created in 2008 by Facebook co-founder Dustin Moskovitz and well-respected software engineer Justin Rosenstein. Their mission: help people organize work activities and projects with a cloud software service that sidesteps email. The Series C round was led by Y Combinator Sam Altman. The round includes both of them as new investors along with a long, who’s-who list of other first-time backers—most of whom use Asana’s software. Among those backers are Palantir co-founder Joe Lonsdale’s venture capital 8VC, Facebook CEO Mark Zuckerberg and his wife Priscilla Chan, Zappos CEO Tony Hsieh (via VTF Capital), Groupon co-founder Andrew Mason, Elevation Partners founder Roger McNamee, and Quora CEO Adam D’Angelo. Get Data Sheet, Fortune’s daily technology newsletter. The new money brings Asana’s total backing to $88 million. It boosts the company’s valuation to $600 million on “clean terms,” Moskovitz touted. The most recent stated figure was $280 million post-valuation following Asana’s $28 million Series B round, which was back in summer 2012, he added. The collaboration software market is pretty broad, worth an estimated $50 billion in size encompassing everything from messaging services to file-sharing apps to project management frameworks like Asana. “The product was born out of our own need to coordinate better: even when we worked at great companies like Google and Facebook, there were constant challenges keeping everyone on the same page, and a huge amount of time spent on work about work,” wrote Moskovitz and Rosenstein in a blog post about the funding. Altman’s motivation was clearcut, boiling down to the product and the team. “I spend a lot of time talking to people who work at startups, and most employees feel like they don’t have a good sense of what specifically the company needs to get done and how all the tasks are going,” he wrote about the investment. “Better work tracking leads to better collaboration and better decision-making.” The same, apparently, could also be said about larger, established companies. Since September 2015 when it introduced a massive redesign for its software, Asana has added close to 3,000 paying customers for a current total of 13,000. One example is the city of Providence, R.I., which has banished internal email in favor of the Asana service to organize tasks and meeting agendas. “I don’t know how any large organization functions without this,” said Mayor Jorge Elorza. “There is no way matters can slip through the cracks,” he added. Approximately 300 people in the Providence administration use the software, which costs it about $5,000 annually, Elorza said. The startup boasts it is generating annual recurring revenue in the “low 10s of millions,” a figure it also cited six months ago. Asana expects to become profitable in the “next few years,” Moskovitz promised. The new funds will go toward scaling Asana’s application and customer support organization so that the software can be used more easily across entire organizations, not just specific divisions, noted Rosenstein. Retailer Zappos, as just one example, uses Asana across its entire organization. The company has signed several other deals supporting more 1,000 seats, Moskovitz said. Two other companies addressing the project management piece of the collaboration software market include Trello, which hopes to reach 20 million users by the end of 2016, and Atlassian team , which went public in December before the tech IPO window basically slammed shut.