Samuel Adams brewer Boston Beer Co., Inc. (NYSE:SAM) released first-quarter earnings earlier this week, and the market initially wasn't pleased.

Shares fell by as much as 10% in Wednesday's early trading following the results, which included better-than-expected 35% net revenue growth to $183.8 million. That was mostly due to impressive core shipment growth of 32%. Earnings per share, however, grew less than 18% over the same period to $0.67, or below analysts' expectations for $0.70. For that, Boston Beer blamed a combination of increased ingredient costs and a huge -- albeit planned -- jump in advertising, promotional, and selling expenses meant to bolster its brands.

As of this morning, though, shares have already recovered most of Wednesday's losses. So why are investors still thirsty for shares of Boston Beer?

And we were surprised... why?
Apart from analysts miscalculating Boston Beer's bottom-line growth this quarter, the report contained no big surprises.

In fact, despite Boston Beer's previous 2014 earnings per share guidance of between $6.00 and $6.40 per share -- which it reiterated this week, by the way -- analysts still went into the report asking for earnings of $6.43 per share. 

The funny thing is, this is almost exactly what happened after Boston Beer's fourth-quarter report in February. Once again, I feel the need to ask: Is nobody listening to what Boston Beer management says?

Don't be afraid of brand-building
Of course, some shareholders are also concerned by Boston Beer's increased marketing investments. This is the same company, after all, whose founding chairman, Jim Koch, says he always keeps in mind his father's advice: "People don't drink the marketing, they drink the beer."

Boston Beer is battling with -- and winning -- market share with Anheuser Busch Inbev

Boston Beer enjoyed a strong debut for its Rebel IPA last quarter. Source Boston Beer Company.

But don't for a second think that Boston Beer is letting its quality slip; it still has pegged between $7 million and $9 million in investments this year for its Alchemy & Science division, which works tirelessly to incubate new craft brews. The fruits of those labors included last quarter's rollout of Samuel Adams Rebel IPA, which -- even though they're still building distribution -- Koch stated is already among the top three best-selling IPAs in the country.

It's also no mystery that as Boston Beer continues to grow, it's facing ever-increasing competition from deep-pocketed industry stalwarts like Anheuser-Busch Inbev (NYSE:BUD), which incidentally owns a significant stake in Craft Brew Alliance, the parent company of Redhook, Widmer Brothers, and Kona Brewing. Anheuser-Busch InBev, for its part, saw its most recent quarter's revenue grow a sluggish 4.6% over the previous year. But that was mostly thanks to a favorable mix in brand sales. A-B Inbev's intelligently managing revenue, even as its beer volumes declined 2% over the same period.

Even so, at this point, it's not hard to see that Boston Beer needs to keep bolstering its marketing efforts to build its brand in the face of powerful competitors. In the end, I think investors will be happy it did.

Foolish takeaway
At least there's a silver lining for patient shareholders of Boston Beer. Namely, that these temporary pullbacks give investors a chance to open or add to their positions at lower price points. Over the long term, I'm still convinced Boston Beer stock has nowhere to go but up.

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