Actually markeedragon is not such a good site for scamming. Why? Because most scammers want only the email to send them a fake blizzard email concerning them selling/trading their account and at markeedragon I do not believe that there is either a way to retrieve the victims personal email nor sending them a message through the markeedragon template.
Will come back later on this actually.
EDIT: This is the MarkeeDragon Template:

Seems to me like you can't send them a "personal message".
Wowtrade.org requires registration. Many (maybe not, but atleast me) scammers might not want to register to websites like these because it's easier to check out other websites. Hope you get my point here. And as you've perhaps noticed, English isn't my mothertongue.
Will however add those sites to the list.
Feel free to come with more suggestions. Preferably in other languages aswell.
Kind Regards,
Aggiish