为什么YQL有效但JSONP不起作用？

I want to make some cross-domain data request. First I tried in YQL and it worked:

<script type="text/javascript">
$(document).ready(function(){
   var myURL = 'http://example.com';
   var xpathVariable = '...';
   var yql = "http://query.yahooapis.com/v1/public/yql?q=" + encodeURIComponent("SELECT * FROM html WHERE url='" + myURL + "'") + "%20AND%20xpath%3D'%2F%2Fdiv%5B%40id%3D%22" + xpathVariable + "%22%5D" + "&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=?";

   jQuery.getJSON(yql, function(data){
      var divToUpdate = $('#container');

      jQuery.each(data.query.results.span, function(i, spanItem){
         $('<div>' + spanItem.content + '</div>').appendTo(divToUpdate);
         if(i == 4) return false;
      });
   });
});
</script>

The result displayed in the div container as expected.

Then I thought I'd give it a try with jQuery's JSONP, here is the code:

<script type="text/javascript">
$(document).ready(function(){
   var myURL = 'http://example.com/search?type=2561&location=1562';       

   jQuery.ajax({
       type: 'GET',
       url: myURL,
       dataType: 'jsonp',
       jsonp: false,
       jsonpCallback: 'requestCallback',                        
       error: function(xhr, status, error){
          alert('error');
       }
   });

   function requestCallback(data){
       console.log(data);
   }     
});

</script>

At this moment, I just want to display the callback json data in the console log, I am not sure what I did wrong as it throws out the error message. Since JSONP fails silently, I couldn't figure out which part of the code was incorrect. Can someone help?

See It is a web service provided by yahoo.As per my knowledge this web service in backend use some web scraping tool by which it will extract data from the url that is provided by you and then give back the extracted data in the form of JSON.