The zone chat is atm just being used as a second trade chat with more visibility because many people don't want to be in the trade chat, so it's just abused as trade. It'd be nice to see it actually being used as zone chat instead of a second trade chat for people who want to bother the people who don't want to be bothered with trades.
Make zone not be trade chat two
This isn't a game with all that many players, and only a small portion of them actually use zone chat like this. That portion, hoiwever, spam it frequently. I'm confident that simply making it a rule and enforcing it sporadically would be enough to make people follow it. At this point, a lot of people are only doing it because others are.
If there's any reason not to do it, a lot of people won't.
It's not a matter of telling each person not to do it. It's a matter of saying it once, publicly, enforcing it once properly, and then sporadically to make sure it doesn't become an issue again. I don't fully know what exact punishments they can hand out, but I'm assuming they can hand out mutes for the in-game chat or similar punishments, which would be plenty of a deterrent to stop people.
Right now maybe it'd be small enough to handle but in the ideal scenario that the game actually grows this would be much harder to handle manually. Deterrence would help some but what about when this game gets 5k active players? What about 10k? What about 25k? The better the game does the harder this will be for GMs to handle manually. The game probably isn't hard to monitor for botting now but if this game explodes in popularity then bots flooding zone and trade chat might become an issue too. Even big MMOs still struggle to combat those things to this day and this game could very well fall victim to that in the future.
I'm not saying this issue shouldn't be dealt with. I'm saying that asking GH to spend resources monitoring zone chats 24/7 will only work for so long and to actually solve this issue forever we need other systems like player managed chat filtering in place.
I completely agree with you but I can already tell you the solution won't be elegant. I've played many MMOs and this is an issue in Every. Single. One. The ONLY game I've seen try to come up with a remotely functional solution is FFXI which has a customizable chat filter you can use on every chat log channel, however the labor of creating the filters is left entirely up to the player to manage. (Tangentially: Kinda shocking such an old game is the only one I've seen have any success tackling this)
If GH tried to moderate it themselves they'd find themselves quickly overwhelmed. Even with the game being as low-population as it is, we'd still need 24/7 monitoring on the zone chats for every instance of haven. Even just a single trader is capable of forcing that.
In the case of chat filtering, traders can be frustratingly resilient. I see that filters can be circumvented within a few weeks by just changing how they format their messages. It's really baffling, but it's just the reality I've observed. Some traders will do everything they can to circumvent your chat filters even though having filters means you very clearly have no interest in their wares. Though player managed filters could work well, you'll need to accept that there's no guarantee you'll never see an ad again where you don't want to and the labor will be your responsibility.
Ideally, people would circulate their own filters for others to use which is what happened in FFXI. It probably won't be as much of a headache as I've portrayed it to be.