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 digital marketing company ValueClick (UNKNOWN:CNVR.DL) plummeted 17% today after its quarterly results and outlook disappointed Wall Street.

So what: ValueClick's first-quarter profit squeaked past estimates, but a top-line miss -- revenue of $165.4 million versus the consensus of $166.7 million -- coupled with downbeat guidance for the current quarter is triggering concerns over slowing growth going forward. While the company continues to increase both earnings and revenue at a solid rate, today's results suggest that it isn't growing fast enough to justify its recent price run-up. 

Now what: Management now sees second-quarter EPS of $0.38-$0.40 on revenue of $164 million-$168 million, versus the consensus of $0.40 and $175.3 million. "Our confidence in accelerating the long-term organic growth profile of the company are still as great as ever," CEO John Giuliani reassured analysts on a conference call. "And that's the key component we want to continue to stress is that the long-term organic growth opportunity is what we're focused on." Of course, with the stock still up more than 100% from its 52-week lows even after today's pullback, I'd hold out for a wider margin of safety before buying into that bullishness.    

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