Are Apple ads hurting Microsoft's brand?

A new ranking of global brands shows Microsoft's reputation sinking in recent years. Among the possible factors: Apple's "I'm a Mac" ads. 

Microsoft lands at No. 59 in the rankings for 2007, down from No. 11 in 2004, according to the survey from CoreBrand released Wednesday. "The effect of Apple's 'Hi, I'm a Mac' advertising campaign may have taken its toll on Microsoft," CoreBrand CEO James Gregory said in a statement.

In fairness to the folks in Redmond, they have fared far better in other recent brand studies. They were No. 1 on a list of Britain's top "superbrands" last year, and No.2 in an August BusinessWeek ranking of top global brands (trailing only Coca-Cola).