When advertising is your main method of monetizing your mobile apps, you want stellar fill rates.
You want to be sure that every ad opportunity is filled up. That every chance you have to show an ad to a user, you HAVE an ad to show them.
The problem is, that when it comes to some ad networks, a 100% fill rate isn't really a 100% fill rate.
Loop de Loop
Showing the same video over and over again should not be considered a 100% fill rate.
Most of the time, when a user has dismissed an ad, they'll most likely dismiss the same ad again.
The same goes for variations of the same ad. Yes, variations are recommended for advertising strategies. But after a person dismisses the variations too, please don't go back to the earlier variation.
Its too bad that many ad networks (even those I have highly recommended before) have removed their fill rates. Something to hide? Questions to avoid?
This "100%" fill rate throws your mediation plans out the window.
Really, how will you get ads allocated to other networks when one particular network keeps showing 100%?
Perhaps its best to go mediation via a neutral provider. Or make your own logic in your code.
(Psst! Bonus tip... its better to mediate with a mixed type of ad network. Often, the same ad campaigns are running across all the CPI based ad networks. If it makes sense to your app, then mix and match between CPI and CPC networks to get a better variation of ads for mediation.)
Here is wishing you a great fill rate!