Originally Posted by
ertyqway
Since I'm usually traveling with my sketching supplies, which include tape, I'm now in the habit of taping a piece of paper over the seatback screen until the DL/Amex spam is done.
It's been a while since I've been on a plane with a seatback screen, but my recollection is that I've been able to turn off the screen, during the Amex commercials, by simply pressing its power button.