As a person who prices and build many bikes, I cant imagine how places like Bikes Direct do it (it's volume, obviously). I have a small shop, and have built around 90 bikes to date for clients. I would imagine the first thing that is skimped on are the wheels?
But, I will say that anything that gets bikes into the hands and under the butts of people is a good thing. Definitely not a snob when it comes to this, and ofter steer my potential clients to BD if their budget dictates...
I dont compete with BD, and never will, but I wonder how they do it.