"Do I really need a professional portrait?" If you are in business, the answer is an emphatic, "Yes!" Potential customers make snap judgements based not only on your website's appearance, but on your appearance. Do you look confident, professional, and approachable? People who are about to invest a lot of time and money into your product want to see the face of who they will work with, and a strong and professional photograph is key. It's a friendly first way to show tentative customers and clients that you are someone who took the time to look your best, and will take that same kind of time to do your best for them.
A poor photograph could be overcome with an upbeat personality or good business skills, but online competition may not allow time to get beyond a first impression. Make the most of that first click by having you yourself featured on your business page, and people will want to know more and stay a while longer.
You aren't one demential, and your professional portraits shouldn't be either. If you have your own business, consider a personal branding session where you'll receive multiple portraits of yourself in various settings showcasing you, your business, and your services. I'll make sure to bring out the best in you, and find the looks that will make your potential customers want to work with you.