Brokerage commissions are a huge expense for most funds.

FORBES: Time��s Running Out For America��s Pensions (May 1, 2003 )

When investors buy or sell mutual funds through discount brokerage firms' "no transaction fee" marketplaces, part of the funds' expense charges are going to compensate the brokerage firms.

WSJ: Questions to Ask Your Financial Adviser About Fees

The conventional stripped-down expense ratio, excluding brokerage, has its defenders.

FORBES: Hidden Expenses

The more you understand how investment research is used by brokerage firms to make them money, the less likely they are to be making it at your expense.

FORBES: Financial Analysts: Writing Research That Benefits Their Employers and Themselves (August 1, 2001)