Why is the salary of sofa factory so high?

The main job of piece sofa factory is to arrange the placement of sponges, take charge of the inventory of departmental sponges and outsourced cotton, and assist in packaging sample sofas. The salary is very good, ranging from 6000 to 12000 a month. Piece work, the more you do, the higher your salary, meals (360/ month), employee birthday parties.