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 Zillow (NASDAQ:ZG) jumped more than 11% early Thursday after the online real-estate specialist's first-quarter results handily beat Wall Street's expectations.

So what: Quarterly revenue rose 70% year over year to $66.2 million, which translated to adjusted net income of $0.02 per diluted share. Analysts, on average, were looking for an adjusted loss of $0.08 per share on sales of just $63.21 million.

For the current quarter, Zillow expects revenue in the range of $75.5 million to $76.5 million. By comparison, analysts were modeling second-quarter sales of roughly $71.8 million. Zillow also expects second-quarter earnings before interest, taxes, depreciation, and amortization of $6 million to $6.5 million.

Finally, for the full year, Zillow raised the midpoint of its previous revenue guidance by $15 million, and now expects 2014 sales of $304 million to $308 million. Once again, that's well above analysts' expectations for 2014 sales of $294.8 million. Meanwhile, Zillow now sees full-year EBITDA of $48 million to $50 million, or an increase of $10 million at the midpoint. 

Now what: Zillow CEO Spencer Rascoff added, "A key driver of Zillow's success lies in attracting audience and delighting our users with great products and services. In March, traffic hit a new high of 77 million monthly unique users as mobile usage more than doubled year over year, and April just broke that record, attracting 79 million unique users."

As it stands, shares of Zillow might look "expensive" trading around 19 times last year's sales and nearly 150 times next year's expected earnings. But that's not particularly alarming for a fast-growing company on the cusp of profitability. In the end, I still like Zillow given its everwidening lead in the online real-estate market, and think shares could prove a bargain for long-term investors even after today's pop.

Steve Symington has no position in any stocks mentioned. The Motley Fool recommends Zillow. The Motley Fool owns shares of Zillow. 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.