Must-read guide to make a good SEO

<!-- *** ADD THIS CODE AFTER YOUR PUBLIC CONTENT *** -->  


<p class="adl-outside-gate">
  Enjoying this so far? Please click one of the buttons below to read the rest. 
</p>


<div class="adl-inside-gate">
  
  <!-- *** REPLACE THIS LINE WITH PRIVATE CONTENT *** -->
  Nice, you found it!


</div>


<!-- Sharing buttons -->
<table>
  <tr>
    <td valign="top">
      <div id="fb-root"></div>
      <script src="http://connect.facebook.net/en_US/all.js#appId=1234&amp;xfbml=1"></script>
      <fb:like href="" send="true" layout="box_count" width="55" show_faces="true" font=""></fb:like>
    </td>
    <td valign="top">
      <a href="http://twitter.com/share" class="twitter-share-button" data-count="vertical">Tweet</a>
      <script type="text/javascript" src="http://platform.twitter.com/widgets.js"></script>
    </td>
    <td valign="top">
      <script src="http://platform.linkedin.com/in.js" type="text/javascript"></script>
      <script type="IN/Share" data-counter="top" data-onSuccess="ADL.viralGate.afterLinkedInShare"></script>
    </td>
    <td valign="top">
      <g:plusone size="tall" callback="afterPlus"></g:plusone>
      <script type="text/javascript">
        (function() {
          var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true;
          po.src = 'https://apis.google.com/js/plusone.js';
          var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s);
        })();
      </script>
    </td>
  </tr>
</table>


<!-- Here is the code -->
<script type="text/javascript">
  ADL = {};
  
  (function(namespace) {
    
    function ViralGate() { };
    
    ViralGate.prototype.setDisplay = function(className, value) {
      var els = document.getElementsByClassName(className);          
      for (var i = 0; i < els.length; i++) {
        els[i].style.display = value;
      }          
    };
    
    ViralGate.prototype.lock = function() {
      this.setDisplay('adl-outside-gate', 'block');
      this.setDisplay('adl-inside-gate', 'none');
    };
    
    ViralGate.prototype.unlock = function() {
      this.setDisplay('adl-outside-gate', 'none');
      this.setDisplay('adl-inside-gate', 'block');          
    }
    
    ViralGate.prototype.afterLike = function(event) {
      // event is the URL
      ADL.viralGate.unlock();
    };
    
    ViralGate.prototype.afterPlus = function(data) {
      // data is object with { href: 'http://...', state: 'on' }    
      if (data.state == 'on') {
        ADL.viralGate.unlock();
      }
    };
    
    ViralGate.prototype.afterTweet = function(event) {
      // event.type == 'tweet'
      ADL.viralGate.unlock();
    };
    
    ViralGate.prototype.afterLinkedInShare = function(url) {
      // url is url string
      ADL.viralGate.unlock();
    }; 
    
    namespace.viralGate = new ViralGate(); 
    
  })(ADL);
  
  ADL.viralGate.lock();
  twttr.events.bind('tweet', ADL.viralGate.afterTweet); 
  FB.Event.subscribe('edge.create', ADL.viralGate.afterLike);
  
  // Google callback must be in global namespace
  afterPlus = function(data) {
    ADL.viralGate.afterPlus(data);
  }
</script>