Be careful with this technique: it can lead to big problems in terms of SEO because even if Google indexes and load AJAX, the easiest way is still to have much of the displayed content in this original HTML file.
But the example is obviously a very good solution and you can even extend it to widgets like Facebook, Twitter and others that may be useful on the desktop version but unnecessary for the mobile version.
Be careful with this technique: it can lead to big problems in terms of SEO because even if Google indexes and load AJAX, the easiest way is still to have much of the displayed content in this original HTML file.
But the example is obviously a very good solution and you can even extend it to widgets like Facebook, Twitter and others that may be useful on the desktop version but unnecessary for the mobile version.