In 1978, The Who asked the musical question, "Who are You?" While the song and album were an exploration of conflicting progressive and punk rock attitudes, nearly 35 years later their query could be the anthem for current sales and marketing angst.
At its most basic level, any operating business has two target audiences: current customers and potential customers. Most proprietors I meet and/or work with operate under a "build it and they will come" approach of one form or another. And for most, it works well in getting a business through its formative stages: establishing a customer base and following, and building a revenue stream.
But to scale an enterprise takes more focus. After all, your target market is not everyone.