I don't honestly know the exact pitch that our sales team is using right now, but in the case of Kiln, stories that show how powerful DVCS is compared to legacy solutions usually make one hell of an impact. You can check out http://www.fogcreek.com/kiln/worldtour2010-dvcsu.html?fccmp=... for example, which is the talk I gave as part of the World Tour. A lot of people who previously didn't "get it", suddenly did.

That can't work for everything, sadly. I know that products that centralize all of your communication, like FogBugz or Flowdock, make one hell of a difference, but it's hard to demonstrate that centralizing communication is helpful if someone doesn't currently believe that.