I blogged about this item recently.
It's about how people are more inclined to fear loss than to be motivated by gain. (And also about how a cheap placebo is less effective than an expensive placebo.)
That was pretty depressing because it seemed like people are hard-coded to not be interested in Openoffice.org (free, and gaining money in the budget to do other things with), when they could clearly benefit from switching from MS Office.
(Caveat. Of course, not everyone should switch from MS Office to OpenOffice.org, but pretty much everyone should consider it.)
However. I'm listening to NPR again and here's the flip side.
People are motivated by fear, by loss. Not just to buy a certain brand of deoderant but it just works. Firefighters who during training are shown or told about the wrong decisions by previous firefighters, ended up performing better than firefighters who were just shown the right decision-making process. Mothers who were told that formula was bad for their babies were more likely to breastfeed than mothers who were told that breastfeeding was good for their babies.
Microsoft certainly does this but without as much emphasis on truth/the whole truth/and nothing but the truth as one might hope.
And when you think about it, it makes sense. Why bother to get up off the chair that's on fire if all you're told is that it's cooler over there on the other side of the room? "You're going to die" is the key information.
So that's one major thing. Emphasize the danger, the disadvantages, of the current choice.
The next major thing I took away from this NPR show is that it's all about "what is everyone else doing." Which is not surprising, but it's very effective. You know the sign you see in hotels, saying please leave your towel on the rack if you want to reuse it. The sign says we should save hot water, save the environment, etc. Hotels in a study increased their towel reuse by guests significantly simply by changing the sign so that it says that 43% (or so) of hotel guests reuse their towels. People look to their peers for approval and guidance of what to do.
Here's a by no means complete but useful list of many implementations of OpenOffice.org. And let's not forget that Sun, Novell, and IBM all have heavy involvement with OpenOffice.org/StarOffice/Symphony.
http://wiki.services.openoffice.org/wiki/Major_OpenOffice.org_Deployments Plus my home town library in Kalispell, Montana; the library uses Userful kiosks. Not a major deployment ;> but it's another stat.
Once you've done the first two things, then of course you need reasons for switching to OpenOffice, or whatever you're trying to explain. And we have those in spades for OOo.