We are just about to launch an online marketplace with a focus on waterfront lifestyle living.
I would recommend creating a meetup or networking opportunity for people interested in your space. This helps you do two things;
1) Get customer feedback from attendees and
2) Build brand awareness.
The other thing you can do is reach out to people who blog about the space and asked to write a guest post about a relevant topic. If you can become a thought leader this will allow you to build a brand while spending little capital.