I can only think of one reason a college football coach would need a business card: to have a business card cool enough that a recruit will say "hey, that's a really cool business card!"
James Franklin of Vanderbilt is covered in that department:
This is cool. Coach Franklin's business card. twitter.com/VandyGold21/st…— Lee Mundy (@VandyGold21) January 15, 2013
That's not even the really cool part - the V logo detaches and is actually A VANDERBILT THROWING STAR. Seriously, everything about James Franklin is pretty great, including the fact that he led Vanderbilt to nine wins, a bowl win, and a top 25 ranking at the end of the year.
Oh, and the other reason a head football coach would want to have a business card is to hand to opposing coaches in post-game handshakes after they win. "Hey, Derek, I'm James: here's my card."
(Missouri quarterback James Franklin's calling card is an interception against Florida.)