I waited to post on a Thursday morning, partly because I didn't want to compete with tons of new stories on a Monday/Tuesday, and partly because I wanted to launch as early as possible and I knew the MVP was basically done.
I let the founders I worked with know I'd be posting on HN, and they were eager to jump in the thread and answer questions that people had about their companies. I think this made the thread a lot more engaging. I also think the interviews themselves really resonated with people on HN, because they have a very "Ask HN" feel to them.
The thread ended up being on the front page of HN for about 36 hours, and stayed in the top 1-3 spots for most of that, finishing with 971 upvotes. (link to HN comments: https://news.ycombinator.com/item?id=12269425) I got about 100,000 pageviews on Thursday and 60,000 on Friday. Someone submitted it to ProductHunt on Sunday morning, where it stayed at #1 all day and got about 20,000 pageviews.
That was 3 weeks ago. Today the site has gotten 283,000 pageviews total. Daily traffic is around 2-3k pageviews (30-50x lower than it was on launch day). I've added a blog, more than doubled the number of interviews, and I'm working on adding a forum. I've also added two sponsors, from whom I've made about $600 total so far.