Who knows about your business? Where can prospects and clients go to learn more? Your website can help establish your business as a going concern, communicate your brand value proposition and it can convey professionalism. It also extends your reach to anyone in the world.
New clients and prospects might want to know about your business history and your expertise and specialization. This is a great vehicle for people to learn more and attain that comfort level they seek.
Providing customers with multiple ways to interact with your business is almost mandatory these days. Anything less could result in lost sales.