There are many types of brokerage fees added in areas such as insurance, realty, delivery services or stocks. Brokerage fees will usually be based on a either a percentage of the transaction or a flat fee. They can also be a combination of the two.
Here is an example of the fee breakdown from a typical stock brokerage:
Stock Price Over $2: $28 flat rate up to 999 shares, 3 cents per share over 999 shares.
Stock Price $2 and Under: 1.4% of principal trade with a minimum of $28 charged.
= brokerage commission