It's not enough that developers are not that interested in bringing their apps to Windows Phone, so Google is now trying to bring down their ad revenues.

Even though the evidence is circumstantial for the moment, something really bad happened that affected lots of Windows Phone developers after the BUILD 2015 conference, WMPU notes.

According to many developers, their fill rates and ad revenues plunged from 99% to only 7%, and 99% to 50% respectively, in just one day.

“My CPM rates and CPC reduced starting on 7/5, really is this error from admob? I am very confused because my revenue dropped more than 50% :(,“ says one developer.

Another developer confirmed the problem, as well as the date where his revenues started falling: “Same here, the fill rate now is kissing the floor. 99% to 7% in one day, also starting on 7/5 (yesterday). May be a bug on Admob network (or a Google conspiration).

Other apps, from other devs, this also happening, the admob ads have disappeared. Are you using the pubCenter? Pay per impression, the fill rate not is good enough, but the CPM is pretty good, for me is better than Admob.”

Google has yet to respond to submitted requests regarding these issues

Although they have submitted requests for these issues related to ad performance and revenue, they did not receive any replies from Google.

The fact that this has started just right after Microsoft announced Android support for Windows 10 Mobile and that it will make it easier for developers to port their apps to its mobile platform looks highly suspicious.

It's also worth mentioning that those affected by these issues were all using AdMob, so the only way to improve the revenues is to use another mobile ad provider like MobFox, Pubcenter and Smaato, though their fill rates are nowhere near AdMob.

Developers affected by the issues are sure that Google is trying to kill Windows Phone because the massive drop in fill rates and ad revenues happened right after BUILD 2015.

Since it's nearly impossible that more than 80% of the advertisers to leave Microsoft's mobile platform in just one day, we reckon there's something really suspicious here.