i have recently viewew google groups beta version . it is a usenet group which let you add link in signature ... lot of peoples are doing it ? is it a good way of marketing ? how large is google groups ( with appx. how many members) ? are they largest ? whatever you post on google groups are displayed in search results ? ?
Google groups has been around for years. It is huge - a quick search around will tell you how large your target niches are. Posts won't appear in main Google search results, but there is a Groups search engine that will find them.
I have a few private groups I run with them. I'm not crazy about the new beta look of it, but probably just b/c I'm used to the old one though. I rarely login anyway, and do it all through email.