You can't really make that generalization.
The point I'm attempting to make is that if something breaks or doesn't work right (from defects, which are possible no matter what you get), you have to pay shipping to send your bike back to bikesdirect. With a LBS purchase, chances are you wont have to pay a single penny if something is messed up. Personally, I had a sticky Tora, then a leaky Tora, and now a perfect Reba, all within a few months of purchasing my bike and I didn't pay anything for any of it. My LBS took care of it (albeit they were very slow about it, but gave me a loaner fork to use in the meantime). I also crashed pretty hard on the bike on my third ride because it wasn't assembled correctly (rookie mechanic), broke and bent a few things, the shop took care of it for free. All flukes, all resolved at no cost to me. If you're the type that doesn't worry about anything bad happening to you, online mail-order bikes are a viable option. Just imagine how much shipping I would have had to pay if my luck would have been the same on a bike purchased online. Not only enough to justify the purchase of the 6500 from a shop, but probably a step or two above it.