In other words, it won't be possible to buy Office 365 University by paying a flat, one-time fee for a perpetual license.

Instead, Office 365 University, scheduled for release in the first quarter, will be available for US$79.99 for a four-year subscription, and will give users the right to install the software to up to two Windows or MacOS computers. Whether they buy it in a store or online, users in the U.S. will download the product from Microsoft data centers and receive rolling, automatic software updates in the same manner.

The release underscores Microsoft's belief that the subscription model represents the future not only for businesses but also for its consumer products. While Microsoft has a longer track record of using this model in the enterprise, it is now starting to push it among consumers.

It remains to be seen whether consumers -- in this case, university students, faculty and staff -- will embrace this model, in which users pay for the right to use the software for a specific time period, usually a year, with the option to renew the license subsequently.

When it announced the new Office in July, Microsoft said that in addition to selling the suite via an upfront, perpetual license -- the product branded Office 2013 -- it would also let people buy the suite as a subscription service, and gave this option the Office 365 brand.