All communications are archived, in a form that cannot be edited. Picture having a single virtual location for all project documents, accessible from almost anywhere. No more questions about whether the concrete people got the latest version of the foundation drawings. Everything flows through the extranet, so everyone knows who answered what, and when. People are less likely to file lawsuits when they know that all the parties have access to the same unchangeable record.
None is as complex as a word processor or a spreadsheet.
He had heard of extranets, and was trying to get his company interested in at least applying them to a pilot project. Sure, it lacked some of the human interface frills of the commercial products. But all the basic functions were there, placing no special demands on FrontPage. Mind you, that is not the path of choice. They are feature-rich, reasonably secure, and free.