Under the document-like school of thought, less "engineers" would need to be employed. Also, less computing resources would be required on both the client side. Money, not to mention time, could be saved.
Perhaps application-like school of thought probably allows for more user manipulation. metrics and tracking.
Not sure about the resources part. One key point in having app like interactions Is that you forego the complete page request/render cycle a document oriented implementation requires.
Perhaps application-like school of thought probably allows for more user manipulation. metrics and tracking.