Good question. I think just for people wanting advice or help with Contax / Yashica cameras. To share equipment sources. To share experience with lenses or cameras. It alerts us all to who else is using the same or similar equipment to our own. To discuss the history of Contax. Infact anything you like about Contax / Yashica.
Just join the group from the Groups link and ask anything you like and we'll see if anyone can answer.