1. I spam them back. I have added a new role which i assign to them. Then i send mass mails to that role constantly. All my deal, offers, FB Post, tweets, updates, you name it they get it.
2. I use the "Admin Tools" plugin to change their Avatar and profile details.
3. And finally, when we see them online we constantly engage them.
The thing is they keep logging back in, which is good for new prospective users, they always see users online.
I have a single moderator, who is collage student and he seems to be having fun with them for now. I do hope some of these suggestions help
I guess, you have applied the most working solution, I give it 5 stars :)
John,
Thanks for advising, we will consider it.