Google offers the Analytics Management library with .NET development in mind. Access resources using either an API Key or OAuth 2.0. To start using the library, study the examples for web applications, service applications, and installed applications. Additional to Analytics Management, this .NET library can be used to interact with more APIs. Choose from an extended list at https://developers.google.com/api-client-library/dotnet/apis/
In Chicago today eBay will kick-off of their annual eBay Developer's Conference by announcing Project Echo, a way for outside developers to integrate their apps "directly onto the world's largest ecommerce site".
Deciding what metrics matter depends on the overall strategy goals and business model that aligns with your APIs. This is why defining the business model was one of the first steps in your decision series. Now we need to make sure our evaluation framework matches back up to what we set out to do.
Our API directory now includes 73 management APIs. The newest is the Jupix API. The most popular, in terms of mashups, is the BuzzData API. We list 6 BuzzData mashups. Below you'll find some more stats from the directory, including the entire list of management APIs.