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 ServiceSource International (NASDAQ:SREV) have flown nearly 19% higher today after the company's second-quarter earnings report came through with a surprise profit after yesterday's close.

So what: Analysts were expecting zero earnings per share for the second quarter, but ServiceSource reported adjusted EPS of $0.02. The company also reported a 13% year-over-year increase in revenue to $67.7 million, above the $64.9 million analyst consensus. The company's GAAP loss was much narrower than it was for the year-ago quarter, with a $0.06 loss per share yesterday against last year's $0.50 loss per share.

The company's full-year guidance was raised on the top line but reduced on the bottom line. ServiceSource now projects between $270 million and $274 million in revenue for 2013, with an adjusted EPS range of $0.05 to $0.07. The new top-line guidance beats the Street's expectations of $269.4 million for the year, but falls short of analyst estimates of $0.08 in EPS for the year.

Now what: It seems like today's buyers are getting a bit ahead of themselves. ServiceSource also projected full-year free cash flow to be between $2 million and $4 million, which at the high end would give the company a forward price-to-free-cash-flow ratio of 242.8. ServiceSource's revenue has only grown about 70% over the past five years. Why does it merit such a nosebleed valuation? I'd tread very lightly around this stock for the time being, especially since it's already doubled over the past year.

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