1) They look professional. A clean, pressed button-up shirt goes with almost everything and looks put together. 

2) They compliment just about anything. Under a blazer, with a cute pencil skirt or even with trouser jeans a button up blouse adds a professional flare to any outfit. 

3) The many styles of blouse provide flexibility. Today blouses come in hundreds of styles and fabrics. Each provides an opportunity to show your unique style.