When you think about your new business, consider how hard you will need to work to get it started, grow it, and make is profitable. The services or products you offer need to be something that you really enjoy.
If a product, you will be spending lots of hours with your product development, packaging, demonstrations, and conversations with prospects. If you have a service and you are providing information to others, you may spend 8 hours a day talking about, researching, writing, preparing proposals, editing materials – all on the subject of your expertise.
In both cases you need to really like your business. And you need to have great expertise in your business. Make a list of the niche areas that you can be the best in the world in. Which one of the items on the list do you really like? This may be the focus of your new business.