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 online marketer ValueClick (Nasdaq: VCLK) jumped as much as 16% in intraday trading after the company had a strong fourth-quarter earnings report.

So what: For the quarter, ValueClick reported year-over-year revenue growth of 17% and earnings per share that climbed 30% to $0.26. Both revenue and earnings solidly beat analysts' estimates. The heady earnings-per-share growth stemmed from the revenue growth combined with cost controls -- including lower year-over-year general and administrative spending -- and a lower share count.

Now what: ValueClick didn't stop there, though. The company also announced first-quarter guidance that cheered investors further. It sees revenue coming in at a midpoint of $112 million and earnings per share notching between $0.16 and $0.17. The revenue guidance is above analysts' estimates, while the expected earnings per share are roughly in line. Trading at just over 20 times current analysts' estimates for full-year 2011 earnings, ValueClick isn't an especially cheap stock. But after 38% growth in earnings per share in 2010, there's little wonder why growth investors might find the stock interesting.

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