I'm surprised this is a retail business. Doing this in conjunction with Digi-Key, Mouser, or Hamilton/Avnet would seem to make more sense. They already distribute the data sheets for the parts they sell. Also, it would be far cheaper to make footprints if you did them in bulk, working your way though long catalogs of similar parts.
Maybe the retail thing is to get some credibility so they can deal with the major distributors.