implementation.js

var bind = function (selector, event) {
  return binder(selector, event);
};

var binder = function (selector, event) {
  var listeners = [];
  
  document.querySelector(selector)
    .addEventListener(event, function (e) {
      listeners.forEach(function (listener) {
        listener.call(this, e)
      };
    });
  
  function addListener () {
    listeners.push(listener);
  };
  
  addListener.selector = selector;
  addListener.event = event;
  
  return addListener;
};

usage.js

// This is basically the same idea behind
// using promises for events, except
// the binding is partially applied so that
// we can send any amount of callbacks to
// the event listener.

var clicked = bind('.element', 'click');

clicked(function (e) {
  
});