It's seemingly impossible to talk about Keurig Green Mountain (UNKNOWN:GMCR.DL) without also bringing up Starbucks (NASDAQ:SBUX) -- so I'm not going to try. What I am going to try to do is convince you that while both companies sell coffee, they're not the kind of competitors that they're often portrayed as. Keurig's in-home focus and Starbucks' in-store focus mean that the success of each contributes to the success of the other.

A virtuous brewing cycle
Keurig's goal isn't to replace the coffee that we buy at cafes. Its goal is to replace the percolators, French presses, and drip coffeemakers that we use at home. The company's stated goal is to provide the "ultimate at-home coffee experience." It's a goal that Keurig has worked toward for years, and it's a goal that is completely compatible with Starbucks' success.

Starbucks packaged coffee makes a mere 3% of sales in its retail outlets and another 7% of total revenue from sales to other retailers. The company has refocused on packaged coffee sales recently, having ended its distribution through Kraft last year. Given that it makes up such a small amount of its total revenue, packaged coffee does offer Starbucks a path to growth, but it's still only a quarter of Keurig's revenue. For comparison, that 7% of total Starbucks revenue amounts to a little over $1 billion last year. Keurig Green Mountain brought in $4.4 billion in total sales in 2013. 

Looking at it the other way, Keurig's revenue has managed to grow even as Starbucks' revenue has grown. The success of Starbucks has not managed to keep Keurig from growing its business. Instead, the two companies have helped grow Americans' appetite for coffee, and both have reaped the rewards of the increased market size.

Risking the reward
Just because Keurig Green Mountain and Starbucks are both on the path to riches doesn't mean investors should jump in with both feet. The businesses do have some clearly defining characteristics. First off, Starbucks is massive when compared to Keurig. Starbucks' annual revenue and market capitalization are both over three times that of Keurig. Investing in Starbucks is investing in an institution, while Keurig -- though not quite a start-up -- is a younger business.

Secondly, Keurig is sitting on the edge of a Coca-Cola deal that's going to open up a whole new world for the business. Starbucks has new offerings in its food and tea lines, which are going to help push the brand forward, but Keurig's Coke deal could be game-changing.

For investors, the choice is between an established powerhouse and an up-and-comer. Both options seem good right now, but there's a speed versus stability choice to be made. I tend to side with Starbucks, but Keurig's future is looking brighter then ever.

Andrew Marder has no position in any stocks mentioned. The Motley Fool recommends Coca-Cola, Keurig Green Mountain, and Starbucks. The Motley Fool owns shares of Starbucks and has the following options: long January 2016 $37 calls on Coca-Cola and short January 2016 $37 puts on Coca-Cola. 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.