Google Apps is now used by more than 20 million students, faculty and staff, according to Nikesh Arora, senior VP and chief business officer at the search giant. Google (NASDAQ: GOOG) barely mentioned Apps during an earnings call earlier this week. But Arora's brief mention shows that enterprises -- particularly colleges, universities and k-12 schools -- continue to embrace the SaaS suite.

Toward the end of the call Arora said:

"The last trend I want to talk about is the trend of cloud computing in the enterprise. Our enterprise business continues to thrive. We saw especially great traction in retail and education sectors this quarter with Dillard's, Kohl's, and Office Depot, all using Google Enterprise products.

In education, there are over 20 million students, faculty and staff on Google apps. [Users include] Princeton, Virginia Tech, and even the Philippines Department of Education, which has over 600,000 users.

With the recent launch of Google+ for enterprise customers, organizations of all size – sizes including capital and Banshee Wines are starting to use our Hangouts and other tools to work together and get things done from anywhere."

Of course, it's difficult to say just how much revenue Google Apps drives for the company. Must pundits believe it's a sub-$500 million business. But that may miss the bigger point: Google Apps puts competitive pressure on Microsoft's cash cow business. In theory, that means Microsoft can't focus all of its attention on Bing, the Google Search alternative.

Also of note: A Google Apps partner ecosystem seems to be thriving. More than 20 percent of the world's top 100 cloud services providers (CSPs) offer Google Apps to their customers.