OK, guess its about time I jump in
I've thought about it and made my choice. Since advertising in the context of our rules is referring to promoting other sites, this case wouldn't necessarily apply. This would be a way to invite all people that have myspace account to join the abandonware group. Sending PMs to all new members is out of the question as that would be spamming, but as far as I am concerned I see no harm in having a signature that invites all myspace members to join this group. So there you have it, I hope that sounds reasonable