In the Debian Edu / Skolelinux project, we have realised that one of the major blockers for the project success is the purchasing skills in schools and municipalities. We provide what the happy users of Debian Edu / Skolelinux say they need and to a lower cost than the alternatives, and yet so few schools decide to use our solution. I was pleased to discover the same observation done by mySociety and Tom Steinberg in his blog post "Can you recognize the million pound chair?". Read it and weep for the spending of your tax money.
Of course there are other factors involved as well, like our projects bad marketing skills and the Linux community fragmentation causing worry with the people on the outside, so we as a project need to keep working hard to gain users, but it is a up-hill battle when public decision makers are unable to understand computer system purchases.