Hi there,
Advertising carries for gold are only pemitted in the Trade (Services) channel. Any carries that are being advertised outside of that channel should be reported to Blizzard.
Blizzard updated the In-Game Advertising Policy when Patch 9.2.7 came out. You may review this policy by Clicking Here.
Also: Any characters that are advertising have to particpate in any runs advertised. Advertising on a Level 1 character for example for a Level 70 carry is not permitted.