Breakpoints

Waltz into a store willing to buy a lot, and you can usually expect a discount or a freebie. The more you spend, the more discounts stores are usually willing to pile on to keep you buying. It works the same way with mutual funds. Buyers of mutual funds can get discounts once they get past breakpoints (the minimum levels where certain discounts are activated). Go past a certain breakpoint, and the commission on the buy might be slashed by 1%. Go above another breakpoint, and the commission will go even lower or disappear entirely. 

Example

Buying shares of One Eyed Man Mutual Fund Company's flagship fund might cost 5.5% commission if you buy less than $25,000 worth. If you buy $500,000 worth of the fund, the commission might just be 1%. Over a million bucks, the commission might be free—the broker will be paid out of the management fee of the company, i.e. One Eyed.