In the real world, the most sensible use for the AdWords API is to integrate with systems that manage massive amounts of advertising. It makes sense to create custom AdWords API web service code if you are managing thousands of campaigns, ads, and keywordson your own account or as an ad agency on behalf of clients.
Complex inventory systems that automatically publish AdWords ads when inventory items meet certain criteriaand revise these ads when an item goes out of stockare also good candidates for automated interaction with the AdWords API.
In either of these cases, or to program any application that interacts with existing AdWords objects, you need to know how to navigate the hierarchy of existing AdWords objects in code. Starting with the authentication information for an account, you can programmatically access campaigns, ads, and the elements that make up ads (such as keywords).
This chapter shows you how to work your way from account information to campaign to AdGroup level, getting as granular as you'd like, all using C# and Visual Studio.NET .