title: Why to use ActionResult
body: <p>I got simple web service application: </p>
  
  <pre><code>public class MyController : Controller
  {
    public ActionResult balance( int amount)
    {
    return Proceed(a.Balance( amount));
    }
  }
  </code></pre>
  
  <p>Just wondering why type <code>ActionResult</code> is used as result. How user can use such type? Why I can't use just simple string?</p>