It should be obvious based on the vertical market you are entering. A wise man once told me (when people were getting crazy about throwing money at Internet start ups back in 2000) "there is no new business. Its all been done before it just takes on new and different forms."
Unless you are a true transformation change agent and have some ultra unique idea that has never been done before look at what the other competitors are doing in your space, pick the most successful one and model your business to a large degree off of that.