Recently I got into a discussion with an American friend about various (e-)sports viewership numbers and we looked up various big sporting events.
Seeing the last Superbowl ranked at an average viewership of 111 million US citizens felt very much inflated, so I did some research and apparently TV ratings are a lot trickier than e-sport ratings where most streaming websites show their concurrent unique and total viewership.
Wikipedia lists USA Today as its source where it states 70% of all household TVs tuned in to Superbowl according to Nielsen. Fox itself, on the same page, claims 113 million (with streams) so these numbers are relatively close.
I also looked up how many TVs are present and on average in the US Nielsen estimates that there are 118 million TVs. 70% of 118 million is not 111 million so I assume 'viewership' has a very specific meaning.
So how did they (Nielsen, Fox) arrive at this viewership number (111 million) and, if it's inflated, what would be a more reasonable amount of unique viewers that tuned in to the Superbowl (2017)