Narrow crown staplers are generally used for finish and trim applications, such as molding, trim, cabinets, drawers, fascias and other fine-grained applications.
 

The smaller crown, like 

Rapid No 606 staple

, allows the stapler to penetrate a surface without being overly noticeable.

For general woodworking projects, brads will be of more use as either a temporary fastener for a permanent fastener for delicate trim. 

Crown staples are used for more specialized applications like for fastening upholstery fabric and attaching roof tiles.

Specially designed for use for electric or pneumatic staplers.