android interstitial ad is not diplaying

Question

android interstitial ad is displaying for test device

AdRequest adRequest = new AdRequest.Builder()
         .addTestDevice("XXXXXXXXXXXXXX")
                .build();
        interstitial.loadAd(adRequest);

But after publishing(removed the "addTestDevice" line), I cannot see any ad. It always returns error code "ERROR_CODE_NO_FILL".(from logcat)

I searched a lot, but couldn't get a satisfactory answer. Is it one of the android's million bugs?

The below is my admob dashboard screenshot. It has some few requests, but no impression. This is not due to my code problem as I am displaying the ad, but loading itself fails after request : ERROR_CODE_NO_FILL

Answer 1

NO_FILL is a standard response. It means that you made a request on the ad network and the ad network has no inventory for you.

The solution is to use mediation to hand off to other ad networks when the first doesn't have any fill. Admob provides a good out of the box mediation.