What does Rule 12b-1 enable mutual funds to do? Is this normally beneficial to current mutual fund

Question:

What does Rule 12b-1 enable to do? Is this normally beneficial to current mutual fund shareholders?
Mutual Funds
Mutual funds are like a pool of funds gathered by different small investors that have simalar investment perspective about returns on their investments. These funds are managed by professional investment managers who act smartly on behalf of the...