Don’t start a business just to start a business. You need to be infatuated with what you are doing or you won’t get people to follow you. Don’t focus on the money. Focus on the passion.
Evernote was at the moment of shutting down, when a mystery man put in further investment simply because he loved the product. This investment propel Evernote to current status and to a product that many cannot live without.
Built a product with passion and you will expect the unexpected. But remember it still has to make money.