Small tip: describe your product in the description of this post and link to it. You might find your first 5 customers here or generate word of mouth. Lost opportunity. Try to be reasonably shameless. If you are solving a problem no one will find you distasteful. People love to be sold good stuff.
We built amazing technology that crawled Yelp, Google, foursquare, Facebook, citysearch, superpages, etc. and we displayed listing info, likes, checkins, ratings, and reviews all in one place. Even better, we let businesses update their info in our dashboard and we pushed it out to the sites. We let them reply to and flag reviews in our dashboard and we posted them on the sites. We spent from 2010 to 2013 building all this tech, and all the devs kept pushing the founders to get it in the hands of customers but they kept insisting that we have a "finished" product first.
So in 2013 when we had all the features in place we launched our beta and while people signed up, in app usage patterns showed they didn't do much. It turns out that small businesses don't really care about anything outside yelp or Facebook (TripAdvisor for some) and they can do that manually. If only we had asked them first...
The next 2 years were spent retooling the app to serve franchise and multilocation customers (the most active customers turned out to be part of bigger chains so we went after these). If the founders had gone out to talk to customers before we started writing code, we could have learned this first.