First, you have to decide if you want to use a computer-centric broadband phone service. The dynamics vary considerably from normal telephone use and from the phone-centric providers discussed in the previous chapter.
Computer-centric broadband phone services primarily benefit groups calling each other over the service. Many Skype users are invited by earlier Skype users, a process Skype makes easy by adding invitations to their web site. SIP-based broadband phone providers rely on business users to define their membership group.