Submitting to reddit/HN when you launch a product is a decision you need to be careful with. You need to time it right to get enough upvotes, you need to target your audience, you need to be ready to handle the traffic, and your product needs to be in a state that's ready for criticism.
This is an encouraging story, but to others out there: be careful! In the words of Eminem, "you only get one shot."
(Of course there are a million other ways to promote other than "Show HN" or reddit posts.)