jQuery.Deferred's monad

deferredmonad.js

(function() {
  function bind(d, f) {
    return d.pipe(f)
  }
  
  function point(a) {
    var d = $.Deferred();
    d.resolve(a);
    return d.promise();
  }
  
  function join(d) {
    return bind(d, function(a) {
      return a;
    });
  }
  
  var inner = point("inner"),
      nested = point(inner);
  
  bind(nested, function(a) {
    alert(a); // [object Object]
  });
  
  bind(join(nested), function(a) {
    alert(a); // inner
  });
})();

This makes more sense to me than the other deferreds-as-a-monad examples I've seen, but now I'm curious what the adjunction is and why it's interesting. It looks like it's just the identity functor (which is a monad).