For the past few months we've been documenting the phenomenal rise of Microsoft Office 365 even in the wake of Google's ambitious plan to nab 80% of Microsoft's Office business.

BetterCloud is about to release another survey that shows Office 365 doing extremely well.

BetterCloud is a cloud service that works with both Google Apps for Work and Office 365 helping IT departments secure and manage them. It regularly surveys its users to uncover cloud usage trends. This time, it queried 1,500 IT professionals who manage either Google Apps for Work or Office 365 for their companies.

It found that bigger, older companies tend to use Office 365, while smaller and younger companies tend to use Google Apps.

Granted, that's not a huge surprise. Bigger, older companies tended to use previous versions of Microsoft Office, so moving employees to a cloud version (which often includes a local copy of Office that runs on the PC offline), is a no-brainer.

Younger people choose Google

The fact that Microsoft is moving its enormous installed base to Office 365 is one of the reasons why Office 365 usage is skyrocketing.

Office 365 surpasses Salesforce as the most deployed app among Okta's 2,000 enterprise customers Okta And it is skyrocketing, according to cloud security company Okta, which provides password management for thousands of cloud applications and thousands of enterprises. In April, Office 365 became the most used app on its network surpassing Salesforce for the first time.

But here's the thing that should be worrying Microsoft: if older companies choose Office, that means that younger companies are choosing Google. And it's not just younger companies, but younger people.

Organizations whose employees average between 18-34 years of age are 55% more likely to use Google Apps than Office 365, the BetterCloud survey finds.

David Politis, founder and CEO of BetterCloud, calls this trend "Growing up Google." And unless Google does something to scare them off, the likelihood that they would en masse ditch Apps for Office isn't high.

"Why would young entrepreneurs make the shift to Office 365 when they have used Google Apps for their entire life?" Politis notes.

Google: bigger bang for the buck

Office 365 users are also more likely to basically ignore the cloud and just use the local version of Office apps installed on their machines.

Google CEO Larry Page; Microsoft CEO Satya Nadella Business Insider/Justin Sullivan/Getty Financially, that doesn't matter to Microsoft – companies pay for Office 365 via an annual subscription whether they use the cloud features or not.

But it does make a financial difference to the companies.

Companies supporting local copies of Office on all their PCs means that they don't get all the cost reducing benefits of using the cloud. This survey finds Google Apps users report double the cost savings for Google Apps than Office 365 users report.

The upshot is that while Microsoft is doing great with Office 365 now, Google has a real shot at being as big or bigger in the not-so-distant future.