&gt; I wonder how long you need to be on a website before they&#x27;ve sent you more HTML data than you would have had to deal with pulling down the Javascript and just pushing JSON data into it. For the mobile web at least, you win.<p>I was talking to a young person that sometimes buys her mobile data plan in 20MB prepaid chunks, complaining how fast Facebook eats through that data.<p>Now I don&#x27;t have Facebook (or a data plan, my ISP has &quot;hotspots&quot; all over town), I was curious and asked her how much Facebook does 20MB buy you, anyway?<p>She said sometimes when she does a full reload of the page it costs 3-4MB. I told her, did you know that&#x27;s enough data to fit the entire LotR trilogy, or the bible? (either of them are about 3-5MB, zipped plaintext).<p>I agree that the things you say could <i>potentially</i> save a lot of bandwidth, but the reality is, in practice they really really do not, not by far :-)