Adcolony ads not working every time

Question

I googled a lot and also i sent a mail to Adcolony
support (http://support.adcolony.com/customer/portal/emails/new), still i didn't get any mail from them.

         I got ads perfectly, but after some time onwards im not getting any ads and also
    getting error message like "**There is currently no fill for zone  zone id with slot
     0**" 
    and also **"Video ad requested but not served in zone zone id with slot 0"**  

   Please assist me, How to get ads on every button tap on ios app.             

Answer 1

The message that you are seeing is normal behavior. When a player has reached the view limits our SDK will display this message. While we make every effort to provide fill for every request, there is no way to guarantee that every button tap will produce an ad play as there are many factors that go into determining ad availability.

Answer 2

Many years passed by, but the problem is still actual.
I tried to use AdColony for the part of users and this error falls quite often.
It means that they have a lack of advertisers and unable to fill your request.
For the banner ads fill rate is really ridiculous.
It resulted in a much smaller profit comparing to the other well-known ad networks (up to 10 times smaller in my case).
I suggest you consider other advertising networks with a better fill rate.