The vast majority of apps in the Windows Phone store are free, paid for via ads.

Now some Windows Phone developers are reporting a precipitous drop in revenue from Google Admob ads around the same time as BUILD 2015.

Fill rates for ads went down from 99% to as little as 7 or 8%, and revenue obviously took a similar plunge of more than 50%.

It is no secret that Google has done everything in its power to stifle Windows Phone, and at BUILD 2015 Microsoft revealed a bold plan to take some of what makes Android popular and use it to boost Windows Mobile.

The drop may be a coincidence but an alternate explanation is that Google may be getting ready to starve Windows Phone developers into submission.

Of course alternative mobile ad providers do exist, including Smaato, MobFox or best of all Microsoft’s own Pubcenter, and in the end these may be the best alternative for those wanting to escape from dependence on Google Ads.

Have our readers who are developers experienced the same drop in revenue? Let us know below.