WeWork is best known as an easy way for small startups to rent office space by the month, but the company is now experimenting with working with huge customers.

On Friday, Microsoft announced it will rent office space from WeWork for 300 of its employees in New York City as well as for a 37-person team in Atlanta. Some Microsoft employees will also have access to WeWork offices in Portland and Philadelphia whenever they need it.

The main goal in New York City is to give the participating Microsoft msft employees—all from its sales department—a more flexible office arrangement. Through their WeWork memberships, they’ll have access to 30 different office buildings throughout the city, where they can book space when they need to stop by and get some work done, or even private conference rooms for client meetings.

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The two companies first started working together at the beginning of the year with WeWork offering access to Office365 to its tenants, or members as it calls them. As part of this continued partnership, WeWork will also start to introduce or test more of Microsoft’s software for businesses. However, WeWork will remain free to work with competing software vendors as well.

“We’re making a big push into bettering our offerings for what we call ‘enterprise customers,'” WeWork chief development officer David Fano tells Fortune. Microsoft is the first large customer WeWork is publicly discussing, he notes.

One advantage of working with big companies like Microsoft is longer financial commitments. While small startups and other tenants usually rent space by the month, Microsoft has a one-year commitment for the New York City memberships for its sales team, and a three-year deal for its Atlanta office space from WeWork. WeWork’s business model has often been criticized for being too volatile because of its short-term tenants, so large enterprise customers might help stabilize some of its business.

In July, Bloomberg obtained documents that showed that WeWork had slashed its 2016 revenue forecast by 14% and that some buildings are opening to tenants later than anticipated, though WeWork tells Fortune that the documents were for scenario planning only and that buildings that have been opened for at least 12 months have 97% occupancy.

This isn’t WeWork’s only departure from its original model. Last month, WeWork vice chair Michael Gross vaguely described at the Cornell Real Estate Conference a new investment vehicle through which the company will purchase some buildings instead of its usual long-term leases, according to a report from real estate news site The Real Deal. Specifically, the company is looking at sale-leasebacks, a form of real estate sale in which the seller then leases the property it originally sold from the new owner. This new vehicle will be funded through new outside investors. A WeWork spokesman declined to share more details beyond Gross’s comments.

Founded in 2010, WeWork has raised more than $1.4 billion, and it is valued at $16 billion.