Launch is only part of the equation. You add/remove features and find where your new users are and find a way to get in front of them. Its a process not a one off launch event. I used to think too much on the launch but my experience says its about the consistent marketing effort.

I launched my subscription tshirt service (https://www.startupthreads.com/monthly) on Hacker news and got a little press but it grew after finding companies each month and finding ways to reach new customers. After iterating a bunch you find out what works, as you'll never have the perfect launch strategy to start.