In the UK there is red button interactive, for extra content not whatever, for example pressing red button during Tennis for different games or the Olympics or World Cup for different event/ matches.
Do they have this is the US and Canada or if not what would be the equivalent, say if you wanted extra content at the end of the show, like if TNA had Impact Wrestling and then at the end you could do something and watch the post show (which is only online I think) is there anything like this for extra content on a show?