Great firms make tradeoffs; they choose what not to do. One key tradeoff that firms make is about the channels through which they decide to sell their products. Premium brands often make an explicit choice to restrict distribution of their products, so as to maintain service quality and preserve the reputation of their brand. As an example, consider Stihl. They are quite blunt about their strategic choice to only sell their products through licensed dealers and not through big box retailers such as Home Depot, Lowe's, or Wal-Mart. Here's an except from their Canadian website:
We can give you over 1,000 reasons - our legion of independent STIHL Dealers nationwide. We count on them every day and so can you. To give you product demonstrations, straight talk and genuine advice about STIHL products. To offer fast and expert on-site service. And to stand behind every product we carry, always fully assembled. You see, we won't sell you a STIHL in a box, not even a big one.
In addition, here's an advertisement that they ran several years ago.