DETROIT – General Motors has decided it won’t advertise in the next Super Bowl, a surprising reversal of strategy that comes as the auto maker overhauls its global marketing operations. GM also announced earlier this week it would no longer advertise on Facebook.

Super Bowl advertising is effective but has become too expensive to justify the cost, GM’s global marketing chief, Joel Ewanick, said in an interview. Buyers say ads for next year’s National Football League championship game?which is being broadcast by CBS?are so far selling for about $3.8 million for a 30-second spot.

It’s an unexpected move for Ewanick, who has long been a big believer in the value of Super Bowl spots, the Wall Street Journal reported.

GM also said this week it would stop paying for advertising on Facebook, and instead rely on the site’s free content, because it felt paid ads did little to influence consumer behavior.

The moves comes shortly after the GM shifted its massive ad buying account to a new agency, cut back on the number of creative agencies that it was using and streamlined the ad production. Ewanick has said that the moves could save the company more than $2 billion over the next five years.

GM is in the process of evaluating all its media properties in an effort to maximize the efficiency of its ad budget, GM spokesman Pat Morrissey said. The auto maker isn’t cutting its ad budget, he said. GM spent $4.47 billion on advertising in 2011, according to the company’s annual report.

GM is the third largest Super Bowl advertisers, following Anheuser Busch and PepsiCo and has shelled out about $82 million on Super Bowl ad time between 2002-2011, according to Kantar Media, an ad-tracking firm owned by WPP PLC.

Ad time for last season’s game in February cost as much as $3.5 million for 30 seconds, according to media buyers.

GM pulled out of the Super Bowl in 2009 when the company’s financial crisis.

While Super Bowl spots are the priciest real estate on TV, most marketers firmly believe it’s worth every penny. Nowadays advertisers are able to get more mileage out of the ad buy because the commercials get so much attention on sites such as Twitter and Facebook.

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