Windows 8 Store apps can deliver periodic or real-time information to you that will be displayed as live notification updates
on your app tiles in Start. Apps that you choose to use as lock screen apps
can also show notification updates on the lock screen.
Store apps that are pinned
to Start can update their tiles with text, images, or text and images. Store apps that are set to show status on the lock screen can update the lock screen with text. This tile information is sent from the app provider to you through Windows Notification Service on Microsoft servers, and is then stored locally on your PC.
This tutorial will show you how to set a monthly data usage limit
for Metro apps live tile updates
for all users in Windows 8
to help reduce your overall metered wireless network
(ex: Wi-Fi, mobile broadband, Bluetooth) monthly data usage. This feature is not available with wired networks (ex: Ethernet).
After you reach the data usage limit set by you, your Metro apps will let you know when there's new info (updates) waiting for you, but your tiles will not update automatically until the next month when your data usage has reset.