Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of cloud-computing specialist (NYSE: CRM) fell as low as 10% on Friday after its quarterly billings disappointed Wall Street.  

So what: Salesforce's third-quarter top and bottom line actually topped estimates, but a miss on billings -- billings grew 29% versus the consensus of mid-30% growth -- suggests that its breakneck business momentum is slowing. Of course, CEO Marc Benioff tried to reassure investors by saying that billings are "not a great indicator of the performance of the company" and that "business is going great."

Now what: In fact, management's current-quarter and fiscal 2013 revenue forecasts easily topped Wall Street estimates. But while Salesforce might have just hit a soft patch, today's sell-off clearly shows just how perfectly it has to perform merely to satisfy Mr. Market, let alone impress him. Given the ever-intensifying competition from cloud-computing gorillas like Oracle (Nasdaq: ORCL) and Google (Nasdaq: GOOG), Salesforce's valuation still doesn't leave much room for error.

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