It identifies when it thinks a user is trying to leave the site by either noting when the user quickly scrolls to the top of the page on mobile or if their mouse starts to move upwards on desktop- even if to open a new thread- it will think you're moving to click off and serve an ad.@BlueDan91 I'm not a techy so you've lost me on all of that but you mention it identifies when a user wants to leave the site. I get various ads, usually Haven and Siemens, when I am trying to open a forum or thread, not when I'm leaving it. Further, it is totally random, which to me suggests a bug or glitch.
These sort of ads also serve when they think a user is idle too.
Quite possibly a bug but everything I've seen of it so far works exactly how I'd expect it to work for that format, I think it was just a little too aggressive with it's triggers.