Can Google Groups be used for commercial purposes? Is there anything against this in its ToS? Are there any major disadvantages to using google groups vs. a mailing list installed on your own server?
It depends on group owners and moderators, probably they doesn't like advertisers... If you think what you offer is helpful to them, ask politely.
Thanks for the reply. I actually meant creating a google group and using it for commercial purposes Such as creating a group to function as a newsletter. Then, sending occasional advertisements with your newsletters via google groups