Yani atıyorum 200 karakterlik bir yazı kopyalanmadığı sürece bu işlem çalışmayacak.
http://jsfiddle.net/jp6nhmxf/
function addLink() {
//Get the selected text and append the extra info
var selection = window.getSelection(),
pagelink = '
Read more at: ' + document.location.href,
copytext = selection + pagelink,
newdiv = document.createElement('div');
//hide the newly created container
newdiv.style.position = 'absolute';
newdiv.style.left = '-99999px';
//insert the container, fill it with the extended text, and define the new selection
document.body.appendChild(newdiv);
newdiv.innerHTML = copytext;
selection.selectAllChildren(newdiv);
window.setTimeout(function () {
document.body.removeChild(newdiv);
}, 100);
}
document.addEventListener('copy', addLink); 
