How exactly is attendance measured these days?
Tickets sold or peeps who turn up?
In England the rules of the premier league say that attendance figures that are publicly reported should be the number of tickets that are issued or sold. Not the number of people who actually attend. (I understand the football league rules say the same, although I couldn’t find the precise clause.)
The actual attendance figure can be quite different to the number of tickets that are issued or sold. Season ticket holders may not turn up for a midweek game. Complimentary, i.e. free, tickets could be issued but not used. People might even walk out in the middle of a match as a protest.