Airbnb is expanding its business travel offering with a deep integration into Concur, the leading enterprise expense-management system.

The companies jointly announced on Thursday that Airbnb listings will start showing up in Concur's travel search results. "This is the first time Airbnb listings will appear on a corporate travel partner's platform," according to the $31 billion startup.

Airbnb's efforts to support its growing B2B division are part of ongoing trend: Consumer-focused gig-economy companies want to serve the enterprise.

By showing up in Concur search results, Airbnb's lodging options will be conveniently distributed to 36,000-plus Concur clients (including 70 percent of Fortune 100 and 500 companies). The volume is significant: In the first quarter of 2017, a busy day for Concur meant "more than 216,000 trips booked," according to the company.

These types of partnerships are win-wins: The startup can access the large, lucrative user base that the larger company has built up over the years, and the larger company is able to offer cutting-edge services to its customers. That said, Airbnb declined to disclose the specifics of its financial arrangement with Concur.

Airbnb and Concur have been working together since late 2014, one of several indications that Airbnb views corporate customers as an important part of its future. "We've grown considerably," global head of business travel David Holyoke said of his division, in an interview with Inc. "Last year we grew at a 3x clip. This year we'll grow at 4x." He added, "We expect to be, by 2020, about 30 percent of Airbnb's [total] business." Currently 15 percent of "nights booked" on Airbnb are work-related, so Holyoke plans to double that within three years.

Airbnb is not the only darling of the sharing economy (or gig economy, if you prefer) that's been courting B2B customers. Ridesharing startup Lyft is aggressively developing features aimed at better serving other companies. Chief business officer David Baga said, "Our goal is to provide reliable, cost effective, and seamless transportation solutions to make Lyft the preferred partner for businesses."

On Tuesday the company announced seven new expense-management integrations, including one with Concur. It makes sense for Lyft to accommodate existing expense-management solutions -- that way it's easier for businesses and their employees to track work-related spending. Larger rival Uber's business offering includes administrative and compliance features, familiar hallmarks of enterprise software.

DoorDash, an online marketplace for on-demand restaurant delivery, has long focused on playing well with other companies. Toby Espinosa, head of national partnerships, noted that "from Buffalo Wild Wings to Jack in the Box and from The Cheesecake Factory to Baskin-Robbins, 40 of the top 100 US restaurant brands now use DoorDash for delivery."

He explained, "In many ways, DoorDash is a B2B business at its core: we've built a best-in-class technology that integrates into a restaurant's operations to help them grow their business and offer delivery across their city." Commission rates are negotiated on a case-by-case basis, but DoorDash typically makes 20 to 30 percent per order from the restaurants it works with.