DraftKings CEO Jason Robins has never been more enthusiastic about the kickoff to the NFL — sports betting's biggest season.It's second only to the Super Bowl in terms of importance for acquiring customers and growing the overall betting pool, Robins told CNBC at the Bank of America Gaming and Lodging Conference."The numbers just keep going up right into kickoff, and it'll continue through Sunday," Robins said. "We're seeing big numbers, record numbers, and we're really excited about what we're going to see ...