Comcast Holdings Corporation engages in the management and operation of broadband communications networks in the United States. The company, over its cable networks, primarily offers various services, including video, Internet, and phone. Its video services include cable network, pay-per-view programming, digital cable, video-on-demand, high definition television, and digital video recorder services. The company's Internet services consist of multiple email addresses, online storage, and various value-added features. Comcast Holdings' phone services comprise traditional circuit-switched local phone service, an array of associated calling features and third-party long-distance services. As of December 31, 2004, the company served approximately 8.5 million cable network subscribers, provided digital cable services to 3.1 million subscribers, and offered Internet services to 2.8 million subscribers. Comcast Holdings also provides installation services and engages in third-party electronic retailing, and Internet connectivity and networked business applications. The company is based in Philadelphia, Pennsylvania. Comcast Holdings Corporation operates as a subsidiary of Comcast Corporation.