I implemented both iAd and AdMob to my project. The structure is if an error comes from iAd server, the app going to show Admob banner or interstitial according to error ad type. Interstitial works fine. But not banners. I used the function shown below and I selected the iAd fill rate to 0% in developer setting of simulator. But it's not writing "WORKED" to console and it's not showing iAd Banner ad(as expected). How can I solve this problem?
func bannerView(banner: ADBannerView!, didFailToReceiveAdWithError error: NSError!) {
println("WORKED")
}