Apply for a broader range of career opportunities. Include your Master's Degree on your resume. With your increased knowledge base achieved from going to school for your Master's Degree, you will have more job opportunities open to you.
Negotiate a raise. If you are working already for a company that you wish to stay with once you finish your Master's Degree, you can negotiate with your current employer for a raise due to your increased education base.
Give yourself a leg up when competing with co-workers for a promotion. If you are currently working and competing for a promotion, having a Master's Degree and letting that fact be known to your employer will give you a better chance of attaining that promotion.
Network with your school's alumnae. When you graduate from an educational institution, you have access to its alumnae database which you can use to gain contacts for new business and job opportunities in the future.