There are two ways in which I think about the question of "reaching" a target audience. First, there's the question of the medium through which you're reaching that audience. Second, there's the message itself -- does it *resonate* with your target audience? These are both important considerations.
You can spend millions getting your message in front of an audience, but if it falls flat, it's a waste of money. So, most importantly, you need to make sure that you have the *right* message. That it resonates.
Achieving this requires listening to customers (specifically, the *right* customers) and articulating, refining and testing your message until you get it right. It can be helpful to take a contrarian or provocative point of view to help make sure your message gets through. You should know it when you have the message right -- it often elicits a "hallelujah!" style response from would-be customers.
Once you're confident you have the right message, then you can apply that message in the different materials and promotional channels that are appropriate for reaching your audience. What those are for your particular company or product will vary, but if the message is right, it will get through.