Blizzard has updated their policy for organized in-game services aka boosting, to prohibit boosting communities that sell and advertise these services in World of Warcraft.
As of today, we will now prohibit organizations who offer boosting, matchmaking, escrow, or other non-traditional services, including those offered for gold. World of Warcraft accounts found to be in violation of this policy are subject to account actions. These actions can include warnings, account suspensions and, if necessary, permanent closure of the disruptive World of Warcraft account(s). Organizations operating across multiple realms and excessively advertising non-traditional in-game sales are contrary to the terms and conditions of the Blizzard End-User License Agreement (EULA).
This will not restrict individual players from using the trade channel to buy or sell services but boosting communities, “especially those who operate across multiple realms” are no longer permitted. How this new policy change will be enforced remains to be seen.
Read the full update on the official WoW forums.