Super Bowl advertisements are still the most expensive on television, but prices for the ads have decreased for just the second time. Pepsi won't advertise for the first time in 23 seasons, joining FedEx and GM, who dropped out last year. TNS Media Intelligence said Monday that a 30-second commercial during next month's Super Bowl on CBS are selling for between $2.5 million and $2.8 million. That's a drop from last year, when ads averaged $3 million on NBC?a record, according to TNS.