The dist centers do not cost as much as you think. They are a small places that handel shipping function, nothing more. Most of Netflix inventory is on shared revenue basis, so not much inventory cost. However, the faster they deliver dvds, the more heavy users they will have. Havey users add to the number of subscribers but lose money for the company. Not a great idea. That is why walmart hasn't built so many dist centers. Not becuase they couldn't affort them. Hopt that helps
NFLX membership is similar to health club membership: while there are 'heavy users', most users will not 'exercise' that much. Speed of distribution would convince new members to join, but how many will keep seeing more than a few DVDs per month?
I for one still have not joined NFLX because: when I want to see a movie, I want to see it w/o delay.
If speed is important to you, you could go to a store to pick up or order from VOD. If speed is not that important but you are lazy to go to the store, you can subscribe to walmart or other fine online dvd rental for less money.