By now you’ve no doubt heard the numbers – $2.5 million for 30 seconds. That’s the record-breaking price advertisers such as FedEx, Pepsi, Burger King, Pizza Hut, and Gillette paid last night for a mere half-minute of your attention – and, of course, that of the other 90 million or so other viewers who were expected to tune in to Super Bowl XL.

As one of the most watched programming slots of the year, the Super Bowl attracts some of the biggest advertising dollars on commercial television. It has become something of an advertising phenomenon, receiving almost as much attention for its commercials as for the game itself. According to a survey released Thursday by consumer research firm ComScore Networks, less than half of the respondents (46%) cited watching the game as their favorite part of the night, and more than a quarter pointed to the advertising as the most enjoyable element.

“This is a rare event where you have tones of eyeballs tuned in, many of which are watching just for the ads,” said John Osborn, president and CEO of BBDO, the ad agency behind many of yester day’s biggest names. “That presents an incredible opportunity to communicate a message to a mass audience that is actually listening.”

Not surprisingly, for those companies forking over the millions, the event is about far more than mere product placement.

For FedEx, which featured a high-definition, 45-second ad depicting a caveman sending a package by attaching it to the leg of a pterodactyl, only to have the bird eaten by a T-Rex mid-flight, the return can’t be measured in dollars and cents. “The payback is much bigger than that,” the director of advertising at FedEx, Steve Pacheco, said. “The Super Bowl is a place for leaders and winners. It’s important for us that our customers and particularly our employees see that we have a presence there. It’s a matter of pride, and it rallies the troops.”

Of course, for companies spending millions to produce and broadcast a 60-, 45-, or 30-second commercial segment, a voice in the Super Bowl telecast is about more than just pride. According to Nielsen NetRatings, advertisers in last year’s Super Bowl collectively experienced a 27% increase in web site visitation in the day following the game. Unique visitor hits rose from 17.6 million on Super Bowl Sunday to more than 22.3 million the next day. And the advertisers know it.

Part of Pizza Hut’s “Cheesy Bites” campaign, in which Jessica Simpson sings a rescored version of her song, “These Boots are Made for Walkin’,” involves the creation of a Web site that allows users to remix their own version of the tune, and then watch Jessica do her thing over and over again until, one assumes, the sight of so much pizza compels a phone call to the local store. It’s actually a whole lot of fun and rather addictive, too.

Pizza Hut paid close to $1 million for Ms. Simpson’s involvement, according to Chief Marketing Officer Tom James, and purchased about 10 spots in the pre-game section of the broadcast. For a fast-food operator like Pizza Hut, the return on investment is immediately measurable (it’s less about abstractions and more about selling pizzas) and the placement pre-game is deliberate – that’s when most people make their food-purchasing decisions.

But the creation of headline-grabbing ads and the use of celebrities is about more than just direct public appeal. An investment in the Super Bowl is all about attention, and the more the better. Celebrities, controversies, and multimillion-dollar budgets are designed to get people talking and journalists writing. Go-Daddy.com made headlines after 13 of its proposed ads were rejected by ABC for being too provocative (the 14th was approved).While it is not being suggested that the company tried deliberately to have its ads rejected, the result certainly didn’t hurt in the publicity stakes. Mr. James of Pizza Hut put it succinctly when he explained why the company chose to use a celebrity – “Jessica Simpson is like catnip to you guys,” he said, referring to the press.

GoDaddy.com isn’t the only advertiser to push the envelope. Others have come under criticism in previous years for what were perceived as crass and sometimes offensive commercials. But perhaps it was just a reflection of the times. “Good Super Bowl ads are like a mirror and reflect what’s going on in pop culture,” BBDO’s president, John Osborn, said. “In the dot-com era you had more outrageous, attention-grabbing commercials. Then, post-9/11, the pulse of the country became more subdued and emotional. Janet took us back to outrageous, but now we’re in a period of uncertainty. I think we’ll see a lot more universal humor this year.”

Judging by the first few commercial breaks – dancing Whopperettes, office mayhem over bottles of Bud Light, Sierra Mist beeping at airport security, and P. Diddy negotiating a recording contract with a bottle of Diet Pepsi, humor is definitely the word. And, this time around, it’s clean.