Competitive advantage: Often overlooked, frequently misunderstood, and generally underappreciated, it may be the most important factor investors should consider before taking a long-term stake in a company. In this video, Motley Fool Co-Founder and Chief Rule Breaker David Gardner presents three critical aspects of competitive advantage -- brand, distribution, and vision -- and looks at companies that possess them in spades

Back in the late 1990s, many people underestimated Amazon (Nasdaq: AMZN), predicting that the company wouldn't last because anyone could come along and build a website that sold books and music. Boy, were they wrong. Similarly, these days, folks might not be seeing the competitive advantage held by online restaurant reservations company OpenTable (Nasdaq: OPEN), which boasts an incredible, perhaps impenetrable, distribution network. And how about the vision of a company like Netflix (Nasdaq: NFLX) and its visionary leader, CEO Reed Hastings, who's been "skating to where the puck is going to be" for as long as critics have been writing off his company as a dead-in-the-water DVD-rental service. Each of these characteristics is essential to long-term business success, and each can be categorized under competitive advantage, one of the most important valued assets a company can have.

Watch the video below.

OpenTable is a Motley Fool Rule Breakers pick. Amazon.com and Netflix are Motley Fool Stock Advisor recommendations. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.