First off, best of luck with your project. Secondly, kudos on writing the post-mortem, as I know it takes some guts to own a "failure".

I think, however, the need to write something like this speaks to an incorrection assumption: you need a "launch". Of course, TC and HN can give you a nice bump in traffic and even signups. However, in the long run, this really doesn't accomplish much for you. It gives you the kind of traffic that will likely leave and move on to the next article, skewing your metrics. There's certainly qualified prospects in there, but it's hard to decipher with all the noise.

Again, the concept of a "launch" speaks to poor business models. It really benefits businesses where the word "traction" is more important than "revenue". Build a business that provides a service that others will pay for and grow as fast as the business can bear, bringing in those visitors that are truly valuable to you.