Cloud computing, with its promise of low-cost delivery, fast implementation, enhanced flexibility and scalability, and better accessibility, had attracted a wide and quick adoption. It is estimated that the cloud computing market will reach $160 billion by 2020. Cloud service providers include major Enterprise Resource Planning (ERP) vendors (e.g., SAP, Oracle) and platform providers (e.g., AWS, Salesforce.com). Despite the fast increase of cloud computing, however, research on cloud computing has just begun. The extant cloud computing research lacks in-depth discussion of company business context and rich knowledge about cloud adoption. To make up for the weakness, we have conducted a case study on the cloud adoption by a large telecommunications company in Canada. Based on the interviews of 20 people who were decision makers or influencers of a cloud adoption, we have identified key factors driving the company to the adoption of a cloud service provided by an external vendor. These factors include fast implementation, flexible technology choice, specialization and continuous innovation, geographical coverage, and local control. The identified key adoption factors are reflective of the company-specific influence. For example, geographical coverage, fast implementation, specialization and continuous innovation are influenced by nature of telecommunications business operations; local control and flexible technology choices, however, suggest the power struggle between the business unit and the internal IT department. Despite the intention of the company to achieve a quick implementation by adopting the external cloud service, at the time when the data was gathered, the implementation was 12-month behind schedule. The business unit that made the cloud adoption decision was remarked as "overly optimistic" about the external solution, and missed some key "foundational work." The findings from the research the fact that the fast and happy path to the cloud adoption may not be fast and happy in the end highlights the drawback of the siloed approached to the cloud adoption, and suggests organizations take a holistic approach in their cloud adoption. We conclude the paper by discussing the contributions of our research to both researchers and practitioners.