A just-announced partnership between Xiaomi and Microsoft represents a potentially promising collaboration between two struggling smartphone businesses.

Starting in September, Xiaomi’s smartphones will ship with Microsoft’s Office apps and Skype, while Xiaomi will receive some much needed patents from the Redmond, Wash., giant. Xiaomi said the cross-license and patent-transfer agreement, which the two companies announced Wednesday morning in China, helps it meet its goal of building relationships with global tech leaders. Microsoft, meanwhile, gets a new platform for its services.

Neither company is approaching this deal from a place of strength. Microsoft is all but irrelevant in smartphones--the global market share for its mobile operating system dropped below 2% last year, says IDC-- while Xiaomi's once ascendant path has stalled.

The deal is most important for Xiaomi’s ambitions of becoming a global consumer brand. Xiaomi's smartphone growth was down 9% year-over-year in the first quarter, according to Counterpoint Research, while growth last year was around 23%, just a hair better than much bigger Apple. For comparison: Xiaomi sold 71 million smartphones in 2015; Apple sold 232 million iPhones. Xiaomi, which a little over a year ago enjoyed the third largest global market share for smartphones, has fallen outside the top 5.

Xiaomi's smartphones haven't been able to match the quality of Apple's or, increasingly, Huawei's in China, and growth is now coming from lower-priced models it sells, in India, Brazil and China. That explains why Xiaomi's total revenues were nearly flat last year compared with the year before, as Fortune reported this month.

The deal for Microsoft's intellectual property is bound to help Xiaomi, which understandably suffers from an IP deficit, being a five-year-old smartphone maker. Because of this deficit, analysts note, Xiaomi was the last of the major Chinese smartphone makers to add a fingerprint sensor to its phones late last year. IP weaknesses have also made Xiaomi wary of entering developed markets where litigation risk is high.

But patents alone won't help Xiaomi successfully expand in the U.S. or Europe.

Xiaomi's core business model--selling phones online at cutthroat prices for no margin, or nearly no margin, in hopes of attracting users to spend on its services--is difficult to replicate outside China. Shoppers in the U.S., for instance, prefer to buy phones in stores. In India, Xiaomi has turned to brick-and-mortar partners. Moreover, Xiaomi's services aren't offered anywhere outside China. Its current operating system is built off of Google's Android platform. Since Google's services are blocked inside China, Google allows Xiaomi to offer its services in place of Google’s inside that country. But outside of China, Xiaomi's phones run with Google's App store and other services.