I believe it would be 99%+.

Just look at the increase in traffic to the shitcoinstalk forum with the mixer ban here. What has happened is that the mixers have gone to advertise elsewhere and with it many forum members who mostly now write on both forums, but if paid campaigns were banned here what would happen is that virtually everyone who writes here would go to write about the same topics to shitcoinstalk, which also has a Bitcoin section, increasingly active.