Google Vulnerable to Shrinking Ad Dollar

SAN FRANCISCO -- Google's(GOOG Quote) tough resilience in the face of economic turmoil may soon be a thing of the past.

The company will post its third-quarter earnings after the close, and while no one expects it to flop, there is less chance of it coming out unscathed the way it always has, to the envy of other Internet companies such as Yahoo!(YHOO Quote) and eBay(EBAY Quote).

In keeping with regular practice -- one that has frustrated many analysts -- Google has not provided any guidance on its results. But Wall Street predicts it will earn $4.80 a share on revenue of $4.05 billion. ...