I've built a site to review & rate beers. It needs some further work & improvements, but I got it out the door. Better to release than to polish to perfection.
There are a number of existing beer rating & review sites. They tend to be a bit dated, but they have great usage.
I've been told, and am a firm believer, that if you take something that already exists and make it better, then you can do well.
But how do you tap into this existing market? People are adverse to change. And are risk adverse. Changing services & losing existing catalogs & data is scary.
All advice welcome.
First, congrats on choosing an established market. This means people are already interested in your idea, they just don't know about you yet.
Your problem is one of audience awareness. You've got to find where your audience congregates (where their watering holes are) and approach them there. What blogs to these folks read? What forums do they participate in? Can you get a beer blogger to mention your site? Can you mention your site in a beer forum?
Additionally, does your site allow the people who do come to easily promote it for you? Social features (Twitter / FB / Quora/ etc) are all the rage for this exact reason.
It is much better to get your product out there and spend your time and effort measuring how people really act using analytics. You can drive yourself crazy worrying about how they might react.
As far as "losing existing catalogs & data" that may or may not be an important issue. If it turns out that it is a major issue keeping people from using your site perhaps you can figure out a way to export the data from the old site and import it into your site?
Before you delay your launch and spend a lot of time building features that people might want, you are probably better to launch and start making money. Once you have money coming in as well as hard data on what is really important then you will be in a better position to make informed choice.
You have a big market, even if you get 1-2% of users that is a lot. You don't need to shoot for 100% on day one. If you are really better, and continue to improve your site, growth will come.
How do you know you made your product better? Did you talk to the users of competing services? Did you ask them what they liked about the sites they currently used, and what they felt could be improved or added?
I had a quick skim through your Twitter feed. You don't appear to have mentioned the site. The Twitter account for your site doesn't appear to be on the front page of the site, and you've made 3 tweets so far this year.
Start talking from your product.
Start Googling "how to build a community".
Become and expert in your niche - beer.
Talk about beer. Lots.
In fact, just do what Gary Vaynerchuk did.