TL;DR
If you've got a Personal or Business license for Construct 2, you can start monetizing with pubCenter ads. You�ll need to create a pubCenter account and install the Microsoft Advertising SDK for Windows 8.
Introduction w/ screenshots: http://ryanjoy.com/2013/05/introducing-a-windows-store-advertising-plugin-for-scirra-construct-2/
Source: https://github.com/atxryan/Windows-8-Advertising-Scirra-Plugin
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<font size="6">Installation</font>
Download the .c2addon file from the GitHub project Plugin directory, then drag and drop the file in to the Construct 2 window. Construct 2 will prompt to ask if you want to install the addon. If you approve the install, you must restart Construct 2 before the addon becomes available.
<font size="6">Tutorial</font>
Add a Windows Store 8 Advertising object to your layout. If this is your first time using the plugin, I recommend leaving the values for size, Application ID, and Ad Unit ID as the defaults in order to test and understand the export process.
<font size="4">Export to Windows 8</font>
Read this tutorial if you need more info on exporting to Windows 8.
Open the Visual Studio solution and right click on References in the Solution Explorer. Choose Add Reference� and check the Microsoft Advertising SDK for Windows 8 (JS). If you don�t see the SDK, you haven�t installed it yet or you may need to restart Visual Studio. Click OK to add the reference to your solution.
After you�ve added the reference, you�ll need to add this line to your index.html just below the base.js and ui.js references:
<font face="Courier New, Courier, mono"><script src="///MSAdvertisingJS/ads/ad.js"></script></font>
You�ll also need to check the Internet (Client) capability in the solutions package.appxmanifest. Obviously your game will need to be able to access the internet if it�s going to show ads!
Note: If you changed the default values for application or ad unit ID, you will not see your ad when you run or test the app. This is due to you using production values. Ads will not run in the simulator using these values to prevent abuse. If you want to see the test ads, you�ll need to use Test Mode values.
Your last step is to update the privacy.html file and submit to the store! Don�t forget you�ll also need to include your privacy policy available from a publicly available website.
<font size="6">Known issues / To-do items</font>
Map all ad SDK events to C2 conditions
Add lat/long coordinate support for localized advertising
Add support for WP8
See GitHub issues or add other on the project's issue's page: https://github.com/atxryan/Windows-8-Advertising-Scirra-Plugin/issues