Does anybody know the Technical reason why?

[Google4Lifee]

Does anybody know the Technical reason why Google does "staged updates"? Such as with the recent Calender/Play Music update... ( I have yet to see them on my Nxxus devices (4 and 10).
And they are doing the same thing with the web based new version of Gmail... and With the 15 gb of Gmail/Drive space. (which i have yet to receive).

Google has more data centers than apple, but yet apple users get updates all at once. WHY?

 

[anon(847090)]

staged updates is a new feature introduced in the play store during the Google IO. its mainly for developers(in this case Google) to release only to few users and test for any bugs.
if there is no bug then they will roll out to all users. this is to avoid people having bad experience with updates.

its purely up to the developers to make use of it.