Ten Reasons Why

First, good old search, then a heirarchical directory, then shopping via Froogle, then email, and now Google is allowing the creation of groups/mailing lists: Google Groups 2 Beta.
The old Google Groups was just an interface to Usenet. This extends it by allowing people to create their own, non-Usenet online discussion groups that can also double as an email listserve.

Greg Technology & Internet