title: Is using a CDN for jQuery (or other static files/scripts) really a good idea?
body: <p>It says everywhere to use a CDN, such as Google's or Microsoft's AJAX CDN to load static script libraries, such as jQuery in my case.</p>
  
  <p>I don't understand how this is really helpful to make my site any faster. In firebug, I'm getting around 300ms both for Google and Microsoft AJAX servers when I load jQuery, and in Chrome, I'm getting around 100ms (dunno what creates the difference, no downloads going on, tried both several times, but anyway that's not the point), my site will have an estimated average of 30 to 40ms response time when I deploy. How can loading the files the CDN do any good to my site? It will make everything even worse!</p>
  
  <p>I understand that when I visit many sites using, say, jQuery from Google's CDN, it will have to "download" the script only once for a very long time, but my browser still tries to connect to the Google's server, and ask for the script file, and then receive 304 not modified status code. During this round trip of 200ms (average of Chrome and FF), I wait. But if I hosted the script file myself, then it will (down)load MUCH faster, about five times, which is an important factor for user experience. Maybe 200ms is not a VERY BIG deal, but it's still a difference and I want to know why it's recommended to use a CDN instead of hosting files ourselves. In the end, after one-time load, the browser will cache the script for my site as well and if I use CDN, browser will ask the CDN for the script anyway which will lag my website.</p>
  
  <p><strong>Update:</strong> I am from Turkey, and that may be the primary reason to have high roundtrips. Most of my visitors will be from here, so I'm asking would it be beneficial for <strong>my site</strong> hosted on servers in Turkey, and <strong>users of my site</strong> who are also at Turkey, to use CDN. Definitely not good for roundtrips, but maybe I'm missing out something.</p>