The only reason you don't have a playoff is because of the bowl tradition and the payouts they have.
You're talking about $200 million in payouts plus another $150 million in TV revenues, sponsorships, etc.. each year. That's a lot of money to play for. Can a playoff make that same amount of money?
The answer is yes. The issue is the format. Mine would be each conference sends it's champion, and you get five at large (since the independents really aren't a conference.)