As far as annual performances go, SodaStream's (Nasdaq: SODA) been more flat than fizzy.

The company behind the home-based soda system closed out 2010 at $31.58. It closed yesterday at $31.57.

The essentially flat showing doesn't mean that SodaStream has been boring. In fact, the stock spent the first half of the year more than doubling before giving it all back in recent months.

It's hard to nail down why the stock hasn't been one of this year's biggest winners.

  • SodaStream has blown past Wall Street's profit targets in all four quarterly reports that it has posted this calendar year.
  • SodaStream's growth proves that it's no 2010 fad. Revenue soared 39% in its latest quarter, and adjusted earnings more than doubled.
  • New retail partners keep coming on as distributors. Staples (Nasdaq: SPLS) and Target (NYSE: TGT) began stocking SodaStream systems and consumables this quarter.
  • The only similar product in the market -- Primo Water's (Nasdaq: PRMW) flavorstation -- has been a financial disappointment for its company.

SodaStream has come a long way from when it seemed as if just Bed Bath & Beyond (Nasdaq: BBBY) and a handful of high-end houseware retailers were championing its cause in the U.S. last year. However, a successful IPO in late 2010 and strong word of mouth helped keep this story stock bubbly. Even Best Buy (NYSE: BBY) began stocking SodaStream systems and syrups this summer.

A flat performance despite the company's positive accomplishments isn't entirely unwarranted. Beverage-maker sales are growing considerably faster than syrup bottles and carbonator refills, suggesting that some buyers do eventually push these manual appliances up to the attic alongside the Margaritaville daiquiri maker and fondue set. However, there have been plenty of times when Green Mountain Coffee Roasters (Nasdaq: GMCR) -- which has a similar model to SodaStream in terms of low-margin starter appliances followed by higher margin consumables -- has sported similar disparities, and no one is dismissing single-cup brewing as a fad these days.

In short, the 2011 scorecard may call this one a draw, but SodaStream's positives outweigh the negatives this year. As part of the CAPScall initiative for accountability, I went ahead and started a bullish call for SodaStream on Motley Fool CAPS. The stock chart may claim otherwise, but 2011 was a good year for SodaStream.

If you want to follow this pop star through its fizz and flat times, add SodaStream International to My Watchlist.