Google's Gotta Hustle to Meet Growth Targets

Continuing spectacular growth at Google(GOOG Quote) will be tougher than Wall Street thinks.

The consensus among sell-side analysts has the company growing earnings by 34% a year
-- for the next five years. That puts Google's price-to-earnings-to-growth ratio -- a measure of its valuation compared to expected growth -- at 1, making it the lowest for large-cap Internet stocks, including companies such as Yahoo!(YHOO Quote) and eBay(EBAY Quote).

But such impressive growth won't be easy. Google is now on track to deliver net income of $4.8 billion this year. Growing such sizable earnings that fast would be a challenge for any company.

At the same time, growth in the search ad market, which has accounted for almost all the company's revenue, is slowing -- particularly in the U.S. ...