Whenever I find myself sitting in Org while waiting for a que, rbg, arena, blah blah blah I used to get really bored. Now i'm on a very populated server and our trade chat goes by faster than Usain Bolt and it remains very busy with lots of advertisements and the like. So instead of sitting there and debating whether or not I should revisit the atrocity that is Runescape 3 in another window, I found a new form of entertainment.
Keep in mind people will scorn you and I always try and target the players who spam "wts 30 day timecard" "selling rbg carries for vicous mount" you know the like.
I always answer trade chat abusers, no matter what, I will probably send at least 70 messages an hour by rapidly replying to every single advertisement, no matter what.
Other: "WTS blah blah 15k"
Me: "I don't have that much money"
Other: "Then why are you messaging me"
Other:"Wts rbg carries, get your vicous mount today"
Me: "No thanks I don't need rbg carries"
Other: "[Insert guild advertisement]"
Me: "I'm already in a guild and your raid times don't work for me"
Other: "sorry to hear that"
*If they continue to advertise in chat I will simply keep replying in varying ways.
It's entertaining to me and I don't think it's breaking the rules in any form. Of course I've been told by my mother, 2 ex-girlfriends and my best friend that I'm a scumbag and irritating. But when your ADHD medicine wears off you aren't just going to sit there quietly.