First, note that we ask “why”, not “if”—this eliminates the chance for people to think they don’t need a business consultant. Use this question to point out all the perks that come from working with a consultant and help people see what value you have to offer for their business. SMBs, especially, can stand to gain a lot of valuable insight because they may not be as familiar with the consulting industry as others in business.
This question gives you a chance to sell your services and show people all that you can do. It also allows you to inform them of just what a business consultant does.