Revision with unchanged content. Call centers have evolved to become the 'first line of defense', at the forefront of modern business. Many companies decide to entrust specialists with ser­vi­cing and building the relationship to their client base. But as customer con­tact is a very sensitive and crucial aspect of the company's long-term success, failures may have damaging consequences. As the personalities of the clients are as varied as their requests, contact centers need to be very flexible. Many control measures used in outsourcing other business functions - such as stan­dardized processes - are therefore not applicable. New standards have to be set and in order to do so, different questions arise: What are the driving factors behind the success of a call center? What are the special characteristics that need to be taken into account? What role does trust play and what measures can be taken to create and build trust? This book gives an overview of the call center industry as business process outsourcing provider and offers answers to the questions above. A study for call centers, their clients and companies who are considering becoming clients.