Blizzard has announced a new policy regarding the advertisement of Boosting and Carrying Services in Patch 9.2.7.
Blizzard
This week the 9.2.7 update introduces the new chat channel: Trade (Services). The Trade (Services) chat channel is used for searching and advertising services like raiding, dungeons, or PvP activities, keeping the original Trade chat channel available for traditional buying and selling of items and profession services.