Advertisers who might have been looking for bargain rates to advertise on NBC's streaming videocast of the Super Bowl a week from Sunday instead will pay more than advertisers who opt for broadcast ad buys. The National Football League is asking for, and getting, $55 cpm, roughly $20 more than NBC is charging advertisers who go the more traditional path. General Motors already has purchased an exclusive on car advertising to stream during the game. Execs expect the game to draw about 100 million TV views and expects an additional 5 million Internet viewers to watch on tablets. Article