About 21 million Americans watched the National Football League's season kick-off game on NBC between the Dallas Cowboys and the New York Giants, while 7.5 million watched Clinton speak during prime-time coverage covered by ABC and CBS, according to Nielsen data reported by Reuters.

But according to Facebook data reported by CNN, Bill ClintonBill ClintonGOP rep: North Korea wants Iran-type nuclear deal Lawmakers, pick up the ball on health care and reform Medicaid The art of the small deal MORE got more mentions on the site than the terms "Cowboys," "Giants," "football" and Cowboys quarterback Tony Romo. Facebook said mentions of Clinton increased by 9,800 percent over the evening.

Facebook has partnered with CNN to provide insight into what Facebook users are talking about up until the election. This week the tool has tracked a spike in Facebook chatter nationwide for President Obama and other Democratic speakers.