NEW YORK (CNNMoney.com) - For many, the suspense leading up to Super Bowl XL in Detroit on Feb. 5 has nothing to do with which teams will make it to the big game but which big corporations will be advertising during it.

Sources have said that Walt Disney (Research)-owned ABC, which will be airing Super Bowl XL, is charging an average of $2.5 million for a 30-second spot, a new record, and that more than 90 percent of the available time has been sold.

Emerald Nuts, which ran a spot with a unicorn during last year's Super Bowl, hopes to make people chuckle this year with an ad featuring a druid and machete enthusiasts.

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A spokeswoman for ABC Sports would not comment on pricing, how many spots are still available or who exactly will be advertising. She added that the network hoped to release an official list of advertisers sometime during the week of Jan. 23.

There had been some concern that advertisers would balk at paying premium prices for the Super Bowl since the Winter Olympics, another high profile media event, will begin only five days after the Super Bowl in Turin, Italy.

In addition, some argue that paying record prices for a Super Bowl ad in this day and age isn't wise since the increased fragmentation of the media -- mainly due to the vast amount of content on the Internet -- makes TV ads less effective in general.

"The problem with Super Bowl advertising now is that companies feel they have to do it because it's their only chance to reach a mass audience," said James McQuivey, a professor at professor at the College of Communications at Boston University. "Prices continue to rise even though the usefulness of the ads have diminished."

Still, several companies have already announced plans to run commercials, including long-time Super Bowl advertisers Anheuser-Busch (Research), Pepsi (Research) and General Motors (Research).

Burger King, which has run several humorous --or creepy, depending on your point of view -- ads throughout the NFL season featuring the King spliced into highlights of actual football games, will be running a 60-second spot. It is the first time Burger King has advertised in the Super Bowl in eleven years, according to the company.

In addition, some smaller companies that advertised for the first time last year, CareerBuilder.com, Emerald Nuts and Ameriquest Mortgage, have said they will be back.

Insurer Nationwide will run its first national ad -- it bought time in select regional markets last year. Toyota is running an ad in English and Spanish for its 2007 Camry. Other advertisers, according to industry trade publication Advertising Age, are Bayer (Research), FedEx (Research) and Unilever (Research).

Tim Calkins, a professor of marketing at Northwestern University's Kellogg School of Management, said the Super Bowl continues to attract top companies, in spite of the Olympics. He says it's a rare event: a time when approximately 90 million people will be paying close attention to the commercials, even if they don't care about the game.

"The Super Bowl still has the biggest media impact. It's a one-shot reach everybody type of event," said Calkins. "A lot of people watch the Super Bowl just for the advertising. People don't watch the Olympics that way."

To be sure, some advertisers -- such as Visa and McDonald's (Research) -- have decided to skip the Super Bowl in favor of the Olympics. But others have decided that advertising during both makes sense.

Michael J. Mendes, the chief executive officer of Diamond Foods (Research), which makes Emerald Nuts, said his company decided to advertise during the Super Bowl and Olympics in order to build on the awareness that they will get from having a Super Bowl spot.

Last year's Super Bowl ad, which featured a unicorn and the Easter Bunny, was a critical favorite, and Mendes said the spot helped sales of Emerald Nuts more than double. This year, Mendes said he hoped the company will have another amusing crowd-pleaser. All he would say was that the commercial features a druid and machete enthusiasts.

The Olympics will run between Feb. 10 and Feb. 26 on NBC and cable networks owned by NBC parent General Electric (Research). Mendes said that the Super Bowl spot and two other ads for Emerald Nuts will run during the Olympics. "The Super Bowl gives us reach, but the Olympics give us frequency," he said.

Nationwide will also advertise during the Super Bowl and Olympics, according to Steven Schreibman, the company's vice president of advertising and brand management. Nationwide's Super Bowl ad, in addition to four others, will run during the Olympics in 27 regional markets, Schreibman said.

Schreibman agreed that a strategy of promoting the company during the Super Bowl and following up during the Olympics makes more sense than just advertising during the Olympics. "The Super Bowl remains the premier advertising showcase of the year," he said. "You can't ignore it."

Nationwide is also hoping to score points with viewers by making them laugh. Schreibman said the Nationwide Super Bowl spot, part of its "Life Comes at You Fast" campaign, will show how quickly fortunes can turn (hence the need for insurance) by featuring male model Fabio.

Humor, as always, is expected to be the dominant theme throughout the Super Bowl ads. With that in mind, Calkins said he is looking forward to the new Emerald Nuts ad as well as the spots from CareerBuilder. Last year's CareerBuilder commercials, featuring chimpanzees, were among the most popular Super Bowl spots.

Still, even though CareerBuilder's commercials were a big hit, the company is currently the only online firm that is planning on running an ad during this year's game, despite the resurgence in fortunes for Internet companies during the past year.

One question mark is GoDaddy.com. The domain registration company ran a risqué ad last year lampooning the Congressional hearings on decency in the wake of the Janet Jackson nipple incident during the halftime show of the 2004 Super Bowl. It is still waiting to see if ABC will approve an ad for this year's game, according to a statement by the company.

"Everyone will be interested to see if GoDaddy is back," said Calkins.

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