I've been thinking along very similar lines, but more along a Github-esque model: Host your data and APIs for free, providing you publish them publicly. If you take them private, you pay a little. Early days yet, today is mostly about gauging interest.
Hehe: I was trying not to use "Like Github for APIs" in my description, but yes, that is pretty much what I was thinking.
I actually just ran the following search on Google:
inurl:.xls site:gov
and uncovered a bunch of random Excel spreadsheets (such as this one: http://www.whitehouse.gov/sites/default/files/omb/budget/fy2...). Would be slightly more complex to do but potentially this would make any published government data instantly accessible via API and (depending on what your backend looks like) you could bake in Solr or ElasticSearch to also provide search inside the data. Maybe an easy onboarding tool to let any visitor to the site specify a publicly accessible spreadsheet and then automatically create the API?
