Later today,Microsoft is going to release RTM of WP7 SDK.Before that,here is an another interesting offering from Microsoft for WP7 developers.Here is the description from MS.
Increase your application revenues with the new Microsoft Advertising SDK for Windows Phone 7. The SDK allow easy integration of text and banner ads into your application, and consumes ads served by Microsoft’s mobile Ad Exchange, the first bidded ad exchange for mobile. The exchange includes multiple advertiser sales channels competing in real-time to purchase your ad inventory, incuding Microsoft’s national sales force and adCenter’s significant market footprint. Microsoft’s best-in-class ad targeting solution means better click through rates and better monetization, and the new SDK is integrated with Microsoft pubCenter to give you actionable reporting of how ads are performing in your applications