She is not as polarizing as Madonna. Her show is not as hyped as Beyonces, some people are going to have no clue that Katy is performing so they won't be ready to switch channels etc. And she is family friendly like Bruno Mars so yeah.
I don't expect her viewers to be underwhelming.. I mean more people are going to watch her just because it's Superbowl, and I don't think Madonna/ Bruno etc. contributed as much to having these huge ratings, than the game itself contributed to it...
Madonna was the exception to that. As the only act with more viewers during the half time show than the game.
I must correct this lie in the name of the KING:
Michael Jackson was chosen to change the Halftime show from being a ratings drop-off point to being the biggest show on Earth in 1993. During his performance, ratings soared for the television broadcast.
Don't know about Madge's or Bruno's.