Like many of the best stocks you've never heard of, Hansen Natural (Nasdaq: HANS) is small and obscure. Unless you're already a Hansen investor like me, you might be surprised to learn that Hansen is the company behind the immensely popular Monster Energy brand.

Last night's fourth-quarter report from Hansen clarified once again exactly how popular Monster is. Net sales increased 14.4% year over year, to $291 million. A 12.2% revenue jump for the core Monster product was complemented by the introduction of a new iced tea product line with the moniker of Peach Tea. The double-digit sales increase was a welcome relief, given that three of the previous four quarters had seen single-digit sales growth. Net income totaled $53.4 million, or $0.57 per share, compared to a year-ago loss of $0.25 per share.

The distribution arrangements that Hansen started up with Anheuser-Busch and Coca-Cola Enterprises (NYSE: CCE) just over a year ago are making a difference on the top and bottom lines. Distribution costs shrank from 4.9% of sales in the fourth quarter of 2008 to 4.1% today. With these powerful partners, distribution levels and market share generally for the Monster Energy brand have increased. Hansen formerly had distribution deals with PepsiCo (NYSE: PEP) and Dr Pepper Snapple (NYSE: DPS), deals the company canceled when it inked its most recent deal.

The fact that Coca-Cola (NYSE: KO) is picking up its bottling partner, Coca-Cola Enterprises, doesn't faze Hansen CEO Rodney Sacks in the least. Indeed, he sees the potential for growth opportunities arising from that deal, especially in new European markets, but there's a lot of complexity in Coke's proposed takeover.

The ubiquity of Monster in American grocery and convenience stores might obscure the fact that the drink isn't widely available in many major markets. We're talking about huge industrialized nations like Brazil and Germany here, and Monster is brand-new to territories like Australia and Ireland. Hansen is going after international opportunities with zest and flair, and that should pay off in renewed growth.

In short, there's plenty of untapped opportunity still ahead of this proven and successful brand. Multinational monsters like Coke and Pepsi have tried and largely failed to break Red Bull's back, but Hansen is doing a fine job of it. Will the next 10 years see Hansen's stock matching the 6,500% returns of the last 10 years? Probably not, since the former small-cap toddler is a mid-cap monster now, but Hansen is still small and successful enough to keep beating the market.

Fool contributor Anders Bylund owns shares in Coca-Cola and Hansen, but he holds no other position in any of the companies discussed here. He's a big dude with a big thirst, OK? Hansen Natural is a Motley Fool Rule Breakers recommendation. Coca-Cola is an Inside Value selection. Coca-Cola and PepsiCo are Income Investor selections. Try any of our Foolish newsletters today, free for 30 days. You can check out Anders' holdings and a concise bio if you like, and The Motley Fool is investors writing for investors.