title: Advantage of using interface as Service contract in WCF
body: <p>i am searching right write up why we need to use interface as Service contract in WCF. i got this url <a href="https://stackoverflow.com/questions/5169915/why-does-net-wcf-service-require-the-interface">Why does .net WCF Service require the Interface</a> and from here i came to know that we can write service contract attribute on class instead of interface.</p>
  
  <pre><code>[ServiceContract]
  public class TheService
  {
     // more stuff here
  }
  </code></pre>
  
  <h2>config entry</h2>
  
  <pre><code>&lt;services&gt;
      &lt;service name="YourServiceName"&gt;
          &lt;endpoint address="" behaviorConfiguration="httpBehavior" binding="webHttpBinding" contract="TheService"/&gt;
      &lt;/service&gt;
  &lt;/services&gt;
  </code></pre>
  
  <p>but very disappointed that not getting all the valid reason like why people often use interface as service contract ?</p>
  
  <p>so just tell me all the advantage we get when we use interface as service contract. so looking for all the valid point for using interface as service contract. so give points with example scenario too because for better understanding. thanks</p>