https://www.wowhead.com/news/boosting-communities-now-prohibited-in-world-of-warcraft-325819Quote
Blizzard
As the conditions change by which various entities operate in World of Warcraft, we are compelled to update our policies to further our goal of making the gameplay experience as fair and welcoming as possible. Since we last updated our policies, we have found that an increasing disturbance of the gameplay experience has been caused by organizations excessively advertising various non-traditional services in-game.
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 policy update does not restrict individuals or guilds from using the provided in-game tools (“trade channel” chat) to buy or sell in-game items or activities for in-game currency. However, “boosting communities”, especially those who operate across multiple realms, are no longer permitted.
We urge all such organizations to cease doing business in World of Warcraft immediately, in order to maintain uninterrupted access to the game.