As soon as you click a chosen select the search input is selected and you cannot add a placeholder anymore, or can you ? 🙂

var $input = $('.chzn-search input');
$placeholder = $('
Type something...
');
$input.after($placeholder);
$input.keyup(function(){
  $placeholder.toggle($(this).val() === '');
});

.chzn-search .placeholder{
  margin-top: -25px;
  margin-bottom: 15px;
  margin-left: 7px;
  color: $gray;
}