Not sure if you missed this in the article you linked to, it was the opening statement to it.
“Even in the face of declining TV ratings, lower attendance and other issues, the National Football League was able to leverage some positive developments into strong sponsorship growth this past year.”
Yes their sponsorship was up last year,overall attendance was down. If attendance keeps dropping then sponsorship will drop. You can slant data anyway you want. People feel the way they feel.