Their comment said it -- SME's (small- and medium-sized enterprises).

There's a gigantic cultural division between SME's where the decision to go Google is a no-brainer (whether starting from in the first place, or switching to at some point in the past 10 years), and large enterprises where the inertia of MS Office is just too great to switch.

What's funny is just how deeply unaware both sides often are of the other -- as both of your comments demonstrate. :)