title: iOS/Swift: more than 10 instances of ADBannerView
body: <p>I am getting this warning after 10 screenviews.</p>
  
  <blockquote>
    <p>More than 10 instances of ADBannerView or ADInterstitialView currently
    exist. This is a misuse of the iAd API, and ad performance will suffer
    as a result. This message is printed only once.</p>
  </blockquote>
  
  <p>I have implemented <code>AdBannerView</code> through InterfaceBuilder. I am <strong>not</strong> explicitely creating an ADBannerView programmatically each time the view is loaded.</p>
  
  <p>I am just referencing the <code>AdBannerView</code> as an @IBOutlet:</p>
  
  <pre><code>@IBOutlet weak var iAdsBanner: ADBannerView!
  </code></pre>
  
  <p>and hiding/showing it by changing its position, as suggested by Apple documentation.</p>
  
  <p>Why am I getting this kind of error?</p>