Talk about cutting it close: NBC said today that it has sold out its TV and digital livestream ad inventory for this Sunday’s Super Bowl. This is unusually late, and an indication that many advertisers looked askance at NBC’s effort to win an average of $4.5 million for a 30-second commercial, a record amount and up 7% from last year.

Fox made its sell-out announcement about two months before it broadcast last year’s game. And NBC was sold out by January 3 in 2012 when it last broadcast the Super Bowl.

In addition to the game, NBC says it has sold out the post-game show, and has just a little inventory left for the pre-game.

NBC expects to record revenues for a Super Bowl sale. Still, NBC Universal News and Sports Group EVP Seth Winter called this “a challenging ad sales marketplace,” and not “the easiest exercise that I have been through.”