It's something I mostly recall from the seventies, but it happened for a while. Comic companies choosing to run advertising on the same page as they'd run the story. Like this.
It wasn't popular, was seen as a bit crass, even for comic books, and it eventually went away.
I understand that DC Comics are planning to run half page double spread ads in their print comics soon. As a result, creators have been told to draft their story breaking in mind that one page will be split into two for the print comic – but also that it will be recombined for the collected edition.
I wonder if geek media buyers Bonfire had a hand in this?
We have all become advert-avoiders to some degree and it's natural for a comic book reader to flip past an ad. But when it is on the same page that you are reading on, this becomes harder so the thought is, the ad will be more effective.