There should be mixers monitoring sites like BestChange.
Interesting. I believe some of such site exist in the darkweb. The problem is finding them.
The clearnet is just a tip of the iceberg compared to the dark web. The problem with the dark web is that it's just too wild for a normal user. Lots of all kinds of things there.
.... So everyone would get the services from there, but it will be hard since Mixer won't offer any affiliates for that.
They would be forced to create affiliate programs since there are no more bitcointalk signature campaigns. In fact, I think I have seen some mixers with affiliate programs.
Also, just because Bitcointalk has banned signature campaigns for mixers does not mean an end to them on the clearnet. There are sites like Quora, Reddit, guru99.com, YouTube, Yahoo Finance etc