In 1979, WPIX of New York experimented with an interactive game for their young viewers in between commercials during afternoon drive programming. Unfortunately, this noble idea didn't last.
TV Pixx lasted a year, and the station utilized Mattel's Intellivision video games for the interstital promotion. Children, with permission from the parents, called in and all they had to do was say, "Pixx" to activate the game. While it was fun at first, and it gave lots of kids bragging rights at school, just for the privelege of saying that they got on TV, even if they physically didn't appear on screen.
The following clip comes from WPIX's anniversary special from a few years back.
If my memory is correct, 2 games were played each hour, and with a 2 hour block (3-5 pm), that meant 4 players a day, 20 per week. I may be wrong about that, but I do know that you had to be a pre-teen to play the game. Living in upstate NY as I do, I couldn't risk a long distance bill to play if I wanted to, since I was too old.