Wal-Mart has revolutionized the retail industry, bringing cheap prices to the public. Those that disagree with this and the job creation have not shopped there nor seen the impact of the economy in the area.
Wal-Mart could do the same with the "Big Bank" industry which takes your money gives you very little in return for it (.5-1% interest for savings) and charges you a exhorbiant interest rate (10-15%) to borrow a loan. They would force an industry change by giving you more interest to save and less interest to borrow then the big banks would ever do.
Ultimately the competition would force change in the current Banking Industry. How many of you have seen New banks being built on every corner in this bad economy. Seems like they are making money to buy all the prime real estate.