I mentioned in on other thread, that they could at least make a PR, blog posts, vlogs, and other crypto-related websites that accepts ad posting on their sites. Since there is no paying signature campaign in other forums, say darknet forums, so i don't think they will keep promoting there like pay per post.
There are social medias whic everyone uses. Plus, a person who knows what a mixer is, definitely knows how to google search a legitimate mixing service.
They can create an account there for regular posting but there's no way they will be accepted to create ads for promotions.