Here's more proof that companies are jumping on Microsoft Office 365 like crazy

Microsoft's Office 365 has become a bona fide success in terms of the number of people starting to use it.

Although there are still some concerns that it will ever be as profitable a business as the Office software it is replacing, Office 365 has officially crossed a new milestone.

It just became the most deployed app on Okta, a cloud service that companies use to manage passwords and employee accounts to other cloud services. Okta has 2,000 customers and since the beginning of 2012, the most popular app has been Salesforce.

"Over the last six to nine months, Office 365 usage has skyrocketed," Okta CEO Todd McKinnon told us in February.

Okta just sent us this updated chart that shows the Office 365 coming from behind to become the No. 1 deployed apps in enterprises:

1. Office 365

2. Salesforce

3. Box

4. Google Apps for Work

Microsoft CEO Satya Nadella also, for the first time also revealed some usage stats about Office 365 for business users.

While he still didn't reveal how many actual business are Office 365 customers, he did say that within those business customers, there were "nearly 50 million Office 365 monthly active users."

That's still a pittance compared to the number of people who were using MS Office in its heyday, which back in 2010 hit about 750 million people.

But it's moving in the right direction.

As businesses switch, many are not buying the Microsoft Office the old way. Microsoft Office commercial revenue was down 16%.

The company isn't breaking out how much revenue it is making from Office 365 business versions yet. It has said that all of its cloud offerings combined are on track to be a $$6.3 billion business this year. Office 365 is a giant piece of that, but not the only piece.

Microsoft also revealed on Thursday how many people are using the consumer version of Office 365: 12.4 million, up 35% over last quarter. The switch also means that consumers aren't buying Microsoft Office the old way. Consumer Microsoft Office revenue from was down 41%.

Meanwhile, its free versions for mobile devices are the most popular of them all. Nadella said there have been 100 million downloads of Office on iPhones, iPads, and Android tablets