The trend we are seeing in Chromebook sales is rather straightforward.
Institutions that switch to using the Google Apps for Work suite of products are very easy to convince to switch to using Chromebooks as well.
Institutions that haven't switched to Google Apps for Work are nearly impossible to sell on the idea of deploying Chromebooks.
So, it's upto Google to convince more people, businesses, and universities that Google Apps are all they need to use. Once that is fate accompli, the decision to use Chromebooks rather than a far less secure, far more expensive, far more difficult to manage platform is rather easy.
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via Answers by Jeff Nelson on Quora,