Dear Mr. Nadella,
Dearest Microsoft Board of Directors,
Especially since you have discontinued Windows Phone, latest Windows 10 Mobile, why not just make the OS charge free?
It does not necessarily need to be the bugs infested Windows 10 Mobile. Most preferably, make Windows Phone 8.1 available for the masses, with Nokia Lumia 620 as a development breadboard.
I can reassure you that with sufficient technical reference material and a free community support, this platform could get more fruitful than it was ever anticipated.
Sincerely yours