xna wp7 advertising

In Visual Studio 2010, I added the following code:

1. Solution Explorer / Reference / AddReference
2. Go to browse & go to: c:\Program Files (x86)\Microsoft SDKs\Advertising for Phone\Libraries\Microsoft.Advertising.Mobile.dll
3. Add this line to the top of the Game1.cs file: using Microsoft.Advertising.Mobile.Xna;
4. then follow the instructions on expansionflow – Incorporating Ads into Your Windows Phone XNA 4.0 Game