These ads disappear when you log in.
Problem with a lot of the serverhop ones, is that Blizz changed server groups so, you have to be in the same 'area' as the leader to get phased to their server.
Well yeah that's been common knowledge & openly discussed since WoD..
This has to be somethin' else.. I'd dare say some abuse or somethin' I'd guess :-/
Since a few months ago , they changed the way this works, you can only server hop if there is a group of players with auto-accept invitation in the area you want to hop in. So basicly you can only use this service now in populated areas.