Many manufacturer's recommend breaking in their brake pads and shoes for better performance and longer life after installation. This process, often called burnishing varies slightly between manufacturers. It generally involves a procedure of 30 slow stops from 30 mph with a 30 second or so cool down.
This insures the vehicle will have a long lasting noise free brake job that performs flawlessly from the start. But not all manufacturer's recommend burnishing replacement pads. Brake pads come in many varieties. Still, it's best not to break in replacement pads with sudden or high speed stops.