A good chunk of the Super Bowl's expected 100-million viewers say they will tune in just for the commercials, but that doesn't mean advertisers can expect a tidal wave of new customers. Some evidence suggests that Super Bowl ads actually fare worse than regular ads at influencing consumers — mostly because companies get too creative for their own good. And at $4 million a spot, that's hardly a good investment.

A study from research firm Communicus, highlighted by AdAge today, found that 80 percent of Super Bowl ads fail to increase sales of their product, a number far higher than the non-Super Bowl failure rate of 60 percent. The study asked consumers their purchasing habits and opinions on brands before the Super Bowl, and then again four weeks later, and found that Super Bowl ads are remembered at a higher rate than regular ones, at 44 percent to 32 percent.

But of those that remembered the Super Bowl commercial, only 35 percent remembered the brand it was associated with. They just remembered the concept. Non-Super Bowl ads, meanwhile, have a brand recall of about 50 percent. So while people remember seeing a specific story, they more often fail to link it to a specific company.

The problem, the study argues, was that Super Bowl commercials are concentrating too much on telling a story or creative idea, and forgetting their main purpose in promoting a specific brand. Communicus CEO Jeri Smith explained:

"The advertisers really dial up the entertainment quotient to pop to the top of the USA Today rankings and such," she said. "But we find the brand association with Super Bowl commercials is much lower than you'd get with a typical buy, just because of the way the creative is structured."

Getting on a "Best Super Bowl Ads" list has its own rewards, but that doesn't necessarily mean the ad succeeded in increasing sales. And at the cost of $4 million per 30-second spot, a raise on last year's $3.8 million price, that can be a costly mistake.

For example, Budweiser's Clydesdale commercial from last season, which showed a young horse growing up, moving away, and then reuniting with its owner, was one of the few to tell a creative story that still emphasized the brand.

With the symbolic Clydesdale horses and Budweiser's red logo everywhere, the ad did well in the study. But Budweiser has been doing this a long time and successes like that are few and far in between. Take, for example, Tide's minute-long commercial last year that told the enjoyable story of a ketchup stain that looked like Joe Montana, until Tide cleans the stained jersey. 
 
The commercial was placed on plenty of Best Of lists, and yet didn't increase sales or intent to buy, according to the study, likely because the Tide logo is hidden until the last few seconds. This type of commercial "run[s] the risk of people being so caught up in the story that they forget about the brand," Smith told AdAge. Similarly, the Dodge Ram "Farmer" ad, though interesting and different, was noticeably light on the brand it was attempting to promote.
 
These warnings won't stop companies from buying more and more costly ads, of course, (which may even be a bargain comparatively, when you consider exposure). But the study suggests that advertisers should be like the Clydesdales in the beer ad, and return to the roots of the job.