1st of all, let me say that 20doc20's post was one of the best I have seen in my short time on SDN. It was informed, balanced, and honest. I cannot replicate his experiences in my own, only to add my own, much lessened, experiences in retail.
I worked in retail for CostCo for 2 years directly out of school. I had done a residency, but was forced by a family situation to an area I would otherwise have no desire to practice in. I know that this is not normal, but at the time I had to sign a contract that stipulated a 200(!!!!) mile radius around a not-so-large NC town. Seeing as I was not planning on staying after my situation had improved, I signed it. The salary was good (83k...this was late 90's) and it was "my own store" so they said. I actually did an interview with what I later learned was a floor manager....if that doesn't seem right to you, read it three more times fast.
With that said, I was given a lot of leeway as far as what to stock, patients to see, etc. The store was opening, and I was there (this was made very clear to me) to give people another reason to come into CostCo. The first year went pretty well....by the time my new contract came due, the game had changed. I was told almost to the person the number of patients I would see, when my new hours would be (saturdays were obligatory now), and was given a new "optical director" that was a terror. She knew nothing of medicine, optometry, anything really; she was a numbers person, pure and simple.
If one would like an example, the prices for EACH FRAME were to be adjusted every month, based on "demand curves" that came from the company. This meant that I would have a patient buy a pair of glasses, pay a certain price, and come back 10 days later (during the switch) and see that the price had halved, or doubled, or usually at least changed by 20-30 dollars....this was the degree to which minutia of money was important to them.
On the medical side, I was told what steps must be taken to shorten my exam times. I am, just by old school, a big fan of doing BIO to every patient. It gives me details that 90D may not pickup....this was axed. It had to be in order to get under their times. I also cut gonio from non-suspects, binoc balance on all pt's, and others, all to get under the line and fight against their current to maintain even basic medical liability standards. For someone that had spent a year plus in a VA hospital residency painstaking over the care of every patient, and given nearly unlimited power for labs, tests, etc, this was soul crushing. I hated optometry more than I could ever explain.
So yes, most schools (very rightly) condemn that model for the destruction it does to our credibility, our pocketbooks, and our progression as doctors. I eventually moved away. I actually took my copy of the contract (will never forget this) to a gun range after my last day. It was that awful for me.
But looking back, I now know the enemy very well. When I started by 1st practice a year or so later (it had crashed and burned, bought it for pennies on the dollar), I had one simple model: Remember CostCo, and do the exact opposite...seems to work so far

hope this helps you understand.