title: Simple jquery ajax vs SignalR vs AspComet
body: <p>I'm reading about long polling, comet etc and, working on .Net, I read all I have found about SignalR and AspComet. I'm a newbie about comet &amp; similar but it is not clear to me what are the advantages in using SignalR or AspComet where i can simply use jquery.ajax/complete: </p>
  
  <pre><code>(function poll(){
      $.ajax({ url: "server", success: function(data){
         doSomething();    
      }, dataType: "json", complete: poll, timeout: 30000 });
  })();
  </code></pre>
  
  <p>but I am clearly missing something here, can you help?</p>
  
  <p>Also, from a system/server point of view what are the main differences? I understand that with $.ajax I open a connection to the server and keep it opened for long (with all the disadvantages of too many open simultaneous connection etc) but I assume SignalR does the same. Or not?
  While, on this, AspComet says that it releases the thread back to the request pool.</p>
  
  <p>I know, I'm a bit confused and an intro about the advantages to use SignalR and/or AspComet vs the $.ajax stuff would be greatly appreciated :)</p>
  
  <p>Thanks!</p>