There are many platforms that mixers can use to conduct promotional campaigns for their services, so I tried to find an explanation as to why they prefer the forums and insist on them, even though most if not all of them cannot be compared to the BitcoinTalk forum, and it can be said that they fail due to the lack of traffic on them.
The only logical explanation that I found is that all the rest of the sites refuse to place advertising banners for Mixers, knowing that as far as I know, there are no laws or legal conditions that prevent them from doing so (at least until now).
Because the community or forum is dynamic, people will stay on to read all the discussions compared to an advertising platform which will only show the platform site or banners, mixers will always have markets, and their clients will follow them on whatever platform they choose just to see if their service is still up to date the proof that they have a huge market is the amount of money they pour just to advertise their service if they can allocate huge funding then there's a big probability that they have existing and loyal clients.
Once they are not yet declared illegal, I believe they will continue to find their root somewhere else and will try as much as possible to be known in some sites that do not care and that are entirely in for the money. But this place is different and I love how things are going now, we have some integrity to protect, at least, not linking us with what is known for much evil is a way forward.
Besides, m!xers' more marketing has started happening, a friend called me 2 days ago that one of the m!xers here has started advertising with some alternatives of Bitcointalk, and that they are offering a very low amount compared to the ones they offered here. Who cares? I didn't even bother to verify. All I know is that they can do it while it lasts and as long as the forums/sites accommodating them are still not locked. But when it starts to be locked, this will be a deterrent for those who still harbour them. I've never been a fan.