question

I am receiving revenues from a few countries on Google Play, in the rest of the world 0% fill rate and consequently the global fill rate decreased drastically. If Amazon doesn't fix the problem quickly I will be forced to remove Amazon Ads and use another ad network.

Did you write to Amazon about this problem? Ads problem is still the same.

Yes, they're having fill rate problems in some countries like Spain and Italy and they're trying to solve it but after too many days the problem is still there. I'm rather annoyed with Amazon ad performance.

Amazon Mobile Ads should be implemented the same for all Android platforms. If an app can receive test ads (testing instructions found here: https://developer.amazon.com/public/apis/earn/mobile-ads/docs/testing-your-app#Testing) but receives a "NO_FILL" error upon trying to load non test ads, there is most likely no issue. It is probable that the app is encountering a scenario where it is having a hard time getting fill. There are many factors that can contribute to a bad fill rate, including the following non integration related factors: - The device could be in a country that does not receive many ads. - The app has not yet received a device identifier (a.k.a. “ad-id”) from Amazon's server due to this being the first time the app requested an ad. - The user may be opted out of personalized ads. - The user could be using an old Android-2.2-era device that is unable to opt in to personalized ads. - The app may be requesting an ad size that has limited fill rate. A typical user’s experience is unlikely to reflect what the developer is seeing. Note that apps with severely restrictive targeting parameters or with a targeted user base in an unsupported country will end up reporting very low fill rates. The Amazon Mobile Ad Network only servers ads to users in the U.S., U.K., Germany, France, Spain, Italy, and Japan. More information can be found here: https://developer.amazon.com/public/apis/earn/mobile-ads/docs/faq.