You know how retailers these days will sometimes solicit customer feedback by handing you a coupon along with your receipt that can only be activated if you call a toll-free number and answer some questions? Well, turns out that DC Comics once tried something similar by including an opt-in survey in its comics. You fill it out and send it in, and theoretically, DC analyzes the information and...well, I don't know. Comes up with new comics, maybe, or adjusts existing titles, or something like that.
What makes this funny is that DC did it in the early 1970s. Go look. It's absolutely hilarious.