I'd just like to echo Ken that "setting up the framework to do crowdsourcing properly itself takes time."  At my institution we have been discussing the use of crowdsourcing to create transcripts of oral histories conducted in the 50s and 60s, but everyone is already overworked and unable to set up the templates, figure out to whom we should issue a call, and then review and edit the products.  Digital sites have the tendency, I think, to make it too easy to envision how much more/else could be done, without accounting for how many more resources might be required to do it.  Without additional resources, crowdsourcing for the <em>Whitman Archive</em> might not be possible without ending work on some other facet of the project.