I have launched a few products. It is really difficult to get the discussion going on many places like reddit or other discourse forums as there are rules against promoting your products. However, I have had huge success with advertising my product ( a paid contact form endpoint service https://liveformhq.com/ ) on another free product (https://getsimpleform.com/) that I built. If you can build a smaller version of your product which provides value to customers it can be a great source of leads :)