An online advertising network connects web content providers and advertisers enabling the providers to monetize their content and the advertisers to reach online consumers. In this paper we study the workings of a successful state-of-the-art online advertising network with branch offices all over the world. The framework is designed to support different targeting strategies and advertising in multiple languages. We describe the implementation of contextual and behavioral targeting, and also discuss different methods to evaluating these strategies. Statistics show that by employing contextual targeting instead of random targeting we can achieve significantly higher CTR values.