> There is no reduction in total work, probably an absolute increase because some logic is duplicated The server is either building a JSON (or some other messa

> There is no reduction in total work, probably an absolute increase because some logic is duplicated The server is either building a JSON (or some other message format) response, or, it could just build the relevant HTML fragment. In many cases, there is no real increase in actual work on the server. Conversely, the client side doesn't need to parse JSON and convert it to a DOM fragment. There's solid reasons for both approaches, depending upon the context.