Satellite is often the only option for rural or exurb broadband Internet: The New York Times reports that Hughes, Starband, and WildBlue have over 390,000 consumers subscribing between them by year's end (240K, 30K, 150K, respectively); WildBlue is adding 15,000 home users and HughesNet 8,000 each month. Installation costs can run $500 with monthly service $50 to $130 per month. The installation costs can be reduced through long-term commitments. Satellite broadband reaches 463,000 households and businesses in all, but will double by 2010.
About 15m U.S. households cannot get broadband service from the local incumbents, this article says. My guess is that number is actually higher, because service availability is usually estimated over broad areas. I have attempted to get DSL service in many places that the line tested as "available," but the service was either marginal or non-existent. This has happened many times to my colleagues as well, and I don't believe we're rare cases, often looking for access in the middle of a city.
The two firms plan to launch new satellites to provide better coverage and access, the Times reports. WildBlue has waiting lists in the midwest and central U.S. where they need more capacity to serve demand. And satellite customers are being slowly picked off as incumbents expand their own coverage as they see demand for wireline service.
Update: This original post stated 150,000 subscribers, but that unintentionally excluded the HughesNet numbers! Thanks to Hughes PR firm for correcting my math.