cio.js

<script type="text/javascript">
  var _cio = _cio || [];

  (function() {
    var a,b,c;a=function(f){return function(){_cio.push([f].
    concat(Array.prototype.slice.call(arguments,0)))}};b=["identify",
    "track"];for(c=0;c<b.length;c++){_cio[b[c]]=a(b[c])};
    var t = document.createElement('script'),
        s = document.getElementsByTagName('script')[0];
    t.async = true;
    t.id    = 'cio-tracker';
    t.setAttribute('data-site-id', 'YOUR SITE ID HERE');
    t.src = 'https://app.customer.io/assets/track.js';
    s.parentNode.insertBefore(t, s);
i  })();
    
	_cio.identify({
      id:         'production_34', // must be unique per customer
      email:      '[email protected]',
      created_at: 1333688268, // seconds since the epoch (January 1, 1970)
      name:       'Joe',
      plan:       'premium'
    });

</script>