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 Inc (NASDAQ:SREV) plunged nearly 33% Friday after the recurring-revenue-management company turned in disappointing first-quarter results.

So what: Quarterly adjusted revenue rose 10% year over year, to $67.3 million, which translated to an adjusted loss of $0.07 per diluted share. Analysts, on average, were expecting a loss of $0.05 per share on sales of $68.56 million. Meanwhile, adjusted EBITDA was a loss of $6.4 million, compared with a loss of $0.5 million in the same year-ago period.

Now what: Though CEO Mike Smerklo insisted Servicesource's "market opportunity and value proposition remain strong," he also admitted first quarter revenue "came in below our expectations and we are moving aggressively to implement operational changes that will better align us with our customers."

That such changes are even required in the first place is a huge concern for long-term investors, especially considering shares already trade around 70 times next year's estimated earnings, even after today's drop. Keeping in mind that those estimates are likely to come down after today's results, I'll be watching this one from the sidelines.

Steve Symington has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.