Ask HN: please rate my failure: Heicos

Today I took off the frontpage of my website the link to the page of the first app I made: Heicos, a mac app to track Zone Diet. Zone Diet is an alimentary lifestyle that is hard to follow because it requires a lot of calculations. So I made this app to ease the burden. After having it available for sale for one year and a half, I just sold three licenses, so it was a complete failure from a sales point of view (but I learned a lot in the process, of course). Taking it down from my website I thought this could be a good occasion for me and other people to learn from my mistakes (I already did learn, of course, but there could be something I missed). Here on HN we speak often about new cool startups/apps but very rarely about projects gone bad. Maybe this can be a valuable topic for someone. Given that Apple is releasing the Mac App Store in the near future, I was wondering if the app is worth another try. I will decide based on the feedback I get from this thread. The page for the app is still available (I will take it down a few days from now, when this thread will be done): http://pawn-soft.com/heicos This was my first application and I wrote it some years ago, when I was very naive. It took me a long time to write it (I was still inexperienced) and when I released it I was very excited and had big dreams of glory and success. But the app never took off. My first error was that I did not have any marketing plan whatsoever. I just followed the old flawed adage "if you build it, they will come", and of course they didn't. I just started shooting in the dark after the first release on my website. The first thing I did was posting it to the Apple website and to other app listing websites (like VersionTracker, Softpedia and the like). I got some traffic and downloads, but not sales. The second action was a press release (through prmac.com). After this I started looking for blogs that targeted the Zone Diet niche, only to discover that it was really hard niche to reach. Almost all the (few) blogs I found were dead from a long time. I wrote to the few that were still active, offering a free license in hope of a review. Of these only a couple answered, but there was never a review. I posted it to the internal Apple website for employees, giving them a free license and, during the whole period, I received 700 license requests, which makes think that maybe the app os not so worthless and there was maybe something flawed in my whole marketing process. After this I started losing faith in the app and I moved to other projects. The software has been downloaded almost 4000 times since the beginning, which could mean that there is some interst in it, but there was never any feedback apart for two emails (yes, only two) just asking to put more food in the initial app database. But these feedbacks came in very lately and filling the app required a lot of long and tedious work, so I never did it considering it not worth the effort, since the app was not selling (maybe this was a big mistake?). After all this, what do you think about it? Is there enough evidence that the project is not worth spending time on it? Or maybe I am just missing something really obvious?