Tiger Woods may be one of the most famous people in the world but he's the greatest disappointment in celebrity product endorsements --- this, according to a recent study commissioned by the trade publication, Ad Age.

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In the study which focuses on celebrity endorsements, Ad Age found that Tiger was the least effective endorser during 2010.

The study closely monitored the impact of all nationally televised ads for the better part of 2010 and discovered "from Tiger Woods to Donald Trump, we found that with rare exception, celebrity endorsements were largely ineffective and failed to yield the benefits popular wisdom promises."

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People are "more likely to be influenced by someone in their social network than a weak celebrity connection," the study contends.

As RadarOnline.com previously reported, on Jan 6 the shamed golfer lost his 13-year endorsement deal with Golf Digest. Prior to loosing that, Tiger was also dropped by Proctor & Gamble, a company for which he promoted Gillette razors and shaving products.

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Also out the door in 2010 -- along with his now ex-wife Elin Nordegren -- endorsement deals with Gatorade, GM and AT&T.

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More than a year after the Tiger Woods cheating scandal broke, RadarOnline.com has learned the shamed golf star has lost his 13-year endorsement deal with Golf Digest.

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“We appreciate the insights Tiger has provided to our readers,” Chairman and Editor-In-Chief of the magazine, Jerry Tarde, said in a statement.

According to reports, there was a disagreement on how many hours Woods could devote to his involvement with the publication, which he was paid an estimated $2 million a year for.

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“The reality is his deal was up at the end of the year,” his agent Mark Steinberg said.