When you show people the ramifications of their decisions, they change their behavior.
Scott Walker's words as he wrapped up the "serious" part of UNLEASH today. (Rich Media awards are up next - I see that a bit more as the "fun" part.) Scott offered a ton of great information showing how rich media can have an impact on going green at your organization. If you missed him today, you might check out his webcast from a few weeks ago, (I highly encourage it.)
I like the quote above because it ties to so many other things that are being discussed here at UNLEASH. For example, in the keynote session, Monty Schmidt talked about how we want to help you find new ways to promoting your content, explore new ways to place content where your audiences are seeking it (or want to use it) - and then offer tools to show the impact of your efforts.
If you can show your boss, your administration, your [insert your whatever here] that what you are doing in webcasting or lecture capture is having an impact - and a very positive one at that - you are going to be much more successful in increasing the use of online multimedia at your organization.
In short - promote the good content that you are capturing. Show people the impact of what you are doing. And, then use that to support the case for doing more.
There are tons of other things being discussed here, but I'm going to give in to the fun. . .