Surface knowledge of your start up target customers is not sufficient. If you want long term success for your new small business, you'll need to dig below the surface of basic customer data descriptions.
Just describing your customers in general terms such as "women over 40" is not enough. Adding more depth to that description gives you a better chance of matching your products and services with a marketing message that resonates. Is that "women over 40" married or single, have children, working outside of the home, etc?
Most products and services you could offer to your target market are available through other vendors. In order to capture a percentage of an existing market place you must communicate with your target customers in a way that conveys your understanding of their needs and interests. That requires an in-depth understanding that surface descriptions can't give you.