Not having a business plan looks like "we'll release a free thing, have no way to generate income, lose money for a few years, and then beg for a million dollars." That's not a business plan. That's a waste of your time & your users' time.
> have you started a successful business?
Not yet, but I am actually working on it! Having a meeting with a local business tomorrow to discuss potential market pricing options so I have some idea of how much money I can expect to make. Business plan!