Many services have access numbers throughout the US and world. A typical dial-in modem operates at speeds up to 56 kps. Make sure the lines you are dialing support the speed of your modem. You may be able to save by paying for a year's service in advance. Cable modem service is much faster and does not tie up your phone line, nor do you need to go through a connection process to get online.
Limited availability exists in many areas.
While provided by an ISP, your phone company must support the service for it to be available. We have found these and other digital subscription services to be more problematic than standard dial-in or cable modem. Most ISPs say they support both Macintosh and Windows, but Mac support may be spotty from some ISPs. Older computers may need memory upgrades, system software upgrades, application software upgrades, etc, and performance will be slow. You may also have problems configuring the software properly.